MIPS: Support `-gnuabi64' target triplet suffix for 64-bit Linux targets

Make the n64 ABI the default for 64-bit Linux targets specified with
`-gnuabi64' suffix included in the target triplet, for configurations
such as the Debian mips64el and mips64r6el ports.  Adjust testsuite
configuration accordingly.

There are the following regressions with the new target triplet:

mips64-linux-gnuabi64  +FAIL: readelf -S bintest
mips64-linux-gnuabi64  +FAIL: MIPS reloc estimation 1
mips64el-linux-gnuabi64  +FAIL: readelf -S bintest
mips64el-linux-gnuabi64  +FAIL: MIPS reloc estimation 1

The `readelf' issue comes from a difference in section headers produced
that the `binutils/testsuite/binutils-all/readelf.s-64' pattern template
does not match.  While there has been a precedent it does not appear to
me that there is a clear advantage from adding more and more variations
to the template rather than forking the existing template into multiple
ones for a more exact match.  So this is best deferred to a separate
discussion.

The MIPS reloc estimation issue is an actual bug in `objdump', which
discards a number of trailing entries from output here for n64 composed
relocations:

DYNAMIC RELOCATION RECORDS
OFFSET           TYPE              VALUE
0000000000000000 R_MIPS_NONE       *ABS*
0000000000000000 R_MIPS_NONE       *ABS*

and consequently `ld/testsuite/ld-mips-elf/reloc-estimate-1.d' does not
match even though ELF output produced is correct according to `readelf':

Relocation section '.rel.dyn' at offset 0x10400 contains 2 entries:
  Offset          Info           Type           Sym. Value    Sym. Name
000000000000  000000000000 R_MIPS_NONE
                    Type2: R_MIPS_NONE
                    Type3: R_MIPS_NONE
000000010000  000300001203 R_MIPS_REL32      0000000000010010 foo@@V2
                    Type2: R_MIPS_64
                    Type3: R_MIPS_NONE

As a genuine bug this has to be handled separately.

Co-Authored by: Maciej W. Rozycki <macro@orcam.me.uk>

	bfd/
	* config.bfd: Add `mips64*el-*-linux*-gnuabi64' and
	`mips64*-*-linux*-gnuabi64' targets.

	binutils/
	* testsuite/binutils-all/mips/mips.exp: Handle `*-*-*-gnuabi64'
	targets.
	* testsuite/binutils-all/objcopy.exp: Handle
	`mips64*-*-*-gnuabi64' targets.
	* testsuite/binutils-all/remove-relocs-01.d: Likewise.
	* testsuite/binutils-all/remove-relocs-04.d: Likewise.
	* testsuite/binutils-all/remove-relocs-05.d: Likewise.
	* testsuite/binutils-all/remove-relocs-06.d: Likewise.

	gas/
	* configure.ac: Handle `mips64*-linux-gnuabi64' targets.
	* configure: Regenerate.
	* testsuite/gas/mips/compact-eh-eb-7.d: Handle
	`mips64*-*-*-gnuabi64' targets.
	* testsuite/gas/mips/compact-eh-el-7.d: Likewise.

	ld/
	* configure.tgt: Add `mips64*el-*-linux-gnuabi64' and
	`mips64*-*-linux-gnuabi64' targets.
	* testsuite/ld-undefined/undefined.exp: Handle
	`mips64*-*-*-gnuabi64' targets.
	* testsuite/ld-mips-elf/attr-gnu-4-10.d: Likewise.
	* testsuite/ld-mips-elf/compact-eh6.d: Likewise.
	* testsuite/ld-mips-elf/mips-elf.exp: Handle `*-*-*-gnuabi64'
	targets.

6 files changed, 20 insertions, 9 deletions

diff --git a/binutils/testsuite/binutils-all/mips/mips.exp b/binutils/testsuite/binutils-all/mips/mips.exp
index 91bf327..fdab971 100644
--- a/binutils/testsuite/binutils-all/mips/mips.exp
+++ b/binutils/testsuite/binutils-all/mips/mips.exp
@@ -125,13 +125,23 @@ if {[istarget *-*-openbsd*] } {
     if [istarget *el-*-*] {
 	set abi_asflags(o32) -32
 	set abi_ldflags(o32) -melf32ltsmip
-	set abi_asflags(n64) "-march=from-abi -64"
-	set abi_ldflags(n64) -melf64ltsmip
+	if [istarget *-*-*-gnuabi64] {
+	    set abi_asflags(n32) "-march=from-abi -n32"
+	    set abi_ldflags(n32) -melf32ltsmipn32
+	} else {
+	    set abi_asflags(n64) "-march=from-abi -64"
+	    set abi_ldflags(n64) -melf64ltsmip
+	}
     } else {
 	set abi_asflags(o32) -32
 	set abi_ldflags(o32) -melf32btsmip
-	set abi_asflags(n64) "-march=from-abi -64"
-	set abi_ldflags(n64) -melf64btsmip
+	if [istarget *-*-*-gnuabi64] {
+	    set abi_asflags(n32) "-march=from-abi -n32"
+	    set abi_ldflags(n32) -melf32btsmipn32
+	} else {
+	    set abi_asflags(n64) "-march=from-abi -64"
+	    set abi_ldflags(n64) -melf64btsmip
+	}
     }
     set irixemul 0
 } elseif {[istarget *-*-linux*] } {
diff --git a/binutils/testsuite/binutils-all/objcopy.exp b/binutils/testsuite/binutils-all/objcopy.exp
index 41add0f..1145835 100644
--- a/binutils/testsuite/binutils-all/objcopy.exp
+++ b/binutils/testsuite/binutils-all/objcopy.exp
@@ -1269,7 +1269,8 @@ if [is_elf_format] {
     run_dump_test "strip-9"
     run_dump_test "strip-12"
 
-    if { [istarget "mips64*-*-openbsd*"] } {
+    if { [istarget "mips64*-*-openbsd*"] \
+	 || [istarget "mips64*-*-*-gnuabi64"] } {
 	set reloc_format mips64
     }
     # A relocation type not supported by any target
diff --git a/binutils/testsuite/binutils-all/remove-relocs-01.d b/binutils/testsuite/binutils-all/remove-relocs-01.d
index 702747b..aeceba1 100644
--- a/binutils/testsuite/binutils-all/remove-relocs-01.d
+++ b/binutils/testsuite/binutils-all/remove-relocs-01.d
@@ -2,7 +2,7 @@
 #source: remove-relocs-01.s
 #objcopy: --remove-relocations=.data.relocs.01
 #readelf: -r
-#notarget: "mips64*-*-openbsd*"
+#notarget: mips64*-*-openbsd* mips64*-*-*-gnuabi64
 
 Relocation section '\.rela?\.data\.relocs\.02' at offset 0x[0-9a-f]+ contains 3 entries:
 .*
diff --git a/binutils/testsuite/binutils-all/remove-relocs-04.d b/binutils/testsuite/binutils-all/remove-relocs-04.d
index 1b8eab3..4ae7a90 100644
--- a/binutils/testsuite/binutils-all/remove-relocs-04.d
+++ b/binutils/testsuite/binutils-all/remove-relocs-04.d
@@ -2,7 +2,7 @@
 #source: remove-relocs-01.s
 #objcopy: --remove-relocations=.data.relocs.0\[12\]
 #readelf: -r
-#notarget: "mips64*-*-openbsd*"
+#notarget: mips64*-*-openbsd* mips64*-*-*-gnuabi64
 
 Relocation section '\.rela?\.data\.relocs\.03' at offset 0x[0-9a-f]+ contains 3 entries:
 .*
diff --git a/binutils/testsuite/binutils-all/remove-relocs-05.d b/binutils/testsuite/binutils-all/remove-relocs-05.d
index a429182..0f35917 100644
--- a/binutils/testsuite/binutils-all/remove-relocs-05.d
+++ b/binutils/testsuite/binutils-all/remove-relocs-05.d
@@ -2,7 +2,7 @@
 #source: remove-relocs-01.s
 #objcopy: --remove-section=.rela.data.relocs.01 --remove-section=.rel.data.relocs.01
 #readelf: -r
-#notarget: "mips64*-*-openbsd*"
+#notarget: mips64*-*-openbsd* mips64*-*-*-gnuabi64
 
 Relocation section '\.rela?\.data\.relocs\.02' at offset 0x[0-9a-f]+ contains 3 entries:
 .*
diff --git a/binutils/testsuite/binutils-all/remove-relocs-06.d b/binutils/testsuite/binutils-all/remove-relocs-06.d
index 5214bc7..f530d30 100644
--- a/binutils/testsuite/binutils-all/remove-relocs-06.d
+++ b/binutils/testsuite/binutils-all/remove-relocs-06.d
@@ -2,7 +2,7 @@
 #source: remove-relocs-01.s
 #objcopy: --remove-relocations=.data.relocs.* --remove-relocations=!.data.relocs.02
 #readelf: -r
-#notarget: "mips64*-*-openbsd*"
+#notarget: mips64*-*-openbsd* mips64*-*-*-gnuabi64
 
 Relocation section '\.rela?\.data\.relocs\.02' at offset 0x[0-9a-f]+ contains 3 entries:
 .*