Set EI_OSABI to ELFOSABI_GNU for local IFUNC symbols

Since the backend elf_add_symbol_hook isn't called on local symbols,
the EI_OSABI field isn't to ELFOSABI_GNU where are local IFUNC symbols.
This patch changes the x86 backends to set has_gnu_symbols if there are
relocations against IFUNC symbols.  Other backends with IFUNC support
may need a similar change.

This patch also changes the type of has_gnu_symbols from bfd_boolean to
enum elf_gnu_symbols.

bfd/

	PR ld/18815
	* elf-bfd.h (elf_gnu_symbols): New enum.
	(elf_obj_tdata): Use elf_gnu_symbols on has_gnu_symbols.
	* elf-s390-common.c (elf_s390_add_symbol_hook): Set
	has_gnu_symbols to elf_gnu_symbol_any.
	* elf32-arm.c (elf32_arm_add_symbol_hook): Likewise.
	* elf32-m68k.c (elf_m68k_add_symbol_hook): Likewise.
	* elf32-ppc.c (ppc_elf_add_symbol_hook): Likewise.
	* elf32-sparc.c (elf32_sparc_add_symbol_hook): Likewise.
	* elf64-ppc.c (ppc64_elf_add_symbol_hook): Likewise.
	* elf64-sparc.c (elf64_sparc_add_symbol_hook): Likewise.
	* lfxx-aarch64.c (_bfd_aarch64_elf_add_symbol_hook): Likewise.
	* elf32-i386.c (elf_i386_check_relocs): Update has_gnu_symbols
	if there are relocations against IFUNC symbols.
	(elf_i386_add_symbol_hook): Don't check STT_GNU_IFUNC here.
	* elf64-x86-64. (elf_x86_64_check_relocs): Update has_gnu_symbols
	if there are relocations against IFUNC symbols.
	(elf_x86_64_add_symbol_hook): Don't check STT_GNU_IFUNC here.

ld/testsuite/

	PR ld/18815
	* ld-i386/i386.exp: Run pr18815.
	* ld-x86-64/x86-64.exp: Likewise.
	* ld-i386/pr18815.d: New file.
	* ld-i386/pr18815.s: Likewise.
	* ld-x86-64/pr18815.d: Likewise.
	* ld-x86-64/pr18815.s: Likewise.

6 files changed, 50 insertions, 0 deletions

diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 0dbdd1e..0a718cf 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -309,6 +309,7 @@ run_dump_test "pr14215"
 run_dump_test "pr17057"
 run_dump_test "pr17935-1"
 run_dump_test "pr17935-2"
+run_dump_test "pr18815"
 
 # Add $PLT_CFLAGS if PLT is expected.
 global PLT_CFLAGS
diff --git a/ld/testsuite/ld-i386/pr18815.d b/ld/testsuite/ld-i386/pr18815.d
new file mode 100644
index 0000000..f49ecf7
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr18815.d
@@ -0,0 +1,9 @@
+#name: PR ld/18815
+#as: --32
+#ld: -melf_i386
+#readelf: -h
+
+ELF Header:
+#...
+  OS/ABI:                            UNIX - GNU
+#pass
diff --git a/ld/testsuite/ld-i386/pr18815.s b/ld/testsuite/ld-i386/pr18815.s
new file mode 100644
index 0000000..ac3377d
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr18815.s
@@ -0,0 +1,15 @@
+	.text
+	.type   selector, %function
+foo:
+	movl	$0, %eax
+	ret
+selector:
+	mov	$foo, %eax
+	ret
+	.type   selector, %gnu_indirect_function
+	.globl	_start
+_start:
+	mov	$selector, %eax
+	call	*%eax
+	ret
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/pr18815.d b/ld/testsuite/ld-x86-64/pr18815.d
new file mode 100644
index 0000000..dd95b2a
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr18815.d
@@ -0,0 +1,9 @@
+#name: PR ld/18815
+#as: --64
+#ld: -melf_x86_64
+#readelf: -h
+
+ELF Header:
+#...
+  OS/ABI:                            UNIX - GNU
+#pass
diff --git a/ld/testsuite/ld-x86-64/pr18815.s b/ld/testsuite/ld-x86-64/pr18815.s
new file mode 100644
index 0000000..6ec79ba
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr18815.s
@@ -0,0 +1,15 @@
+	.text
+	.type   selector, %function
+foo:
+	movl	$0, %eax
+	ret
+selector:
+	mov	$foo, %eax
+	ret
+	.type   selector, %gnu_indirect_function
+	.globl	_start
+_start:
+	mov	$selector, %rax
+	call	*%rax
+	ret
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index d67ff2a..bd48cd3 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -325,6 +325,7 @@ run_dump_test "pr17935-1"
 run_dump_test "pr17935-2"
 run_dump_test "pr18160"
 run_dump_test "pr18176"
+run_dump_test "pr18815"
 
 # Add $PLT_CFLAGS if PLT is expected.
 global PLT_CFLAGS