sim: Fix use of out-of-tree assembler and linker when testing

With commit 7a259895bb2d "sim: testsuite: expand arch specific
toolchain settings", trying to use out-of-tree ld and as at test-time
broke for the "primary target", like when testing a release-tarball.

Subsequent to that commit, all assembler tests without in-tree-built
tools FAIL, getting errors when trying to call
$(abs_builddir)/../gas/as-new.  But, that isn't the actual culprint;
it's actually it's its immediate predecessor, commit 8996c21067373
"sim: testsuite: setup per-port toolchain settings for multitarget
build", which hardcodes in-tree-paths to those tools instead of
considering e.g. $(<X>_FOR_TARGET), the preferred overridable variable
for single-target builds, as set up by the toplevel Makefile.

This commit calls GCC_TARGET_TOOL (a deceptive name; gcc-specific
features aren't used) from toplev/config/acx.m4, somewhat like calls
in toplev/configure.ac but without the NCN_STRICT_CHECK_TARGET_TOOLS
step, for each X to find a value for $(<X>_FOR_TARGET).  N.B.: in-tree
tools still override any ${target}-${tool} found in $PATH, i.e. only
previously broken builds are affected.

The variables $(<X>_FOR_TARGET) are usually overridden by the toplevel
Makefile to the same value or better, but has to be set here too, as
automake "wants" Makefiles to be self-contained (you get an error
pointing out that the variable may be empty).  If it hadn't been for
that, SIM_AC_CHECK_TOOLCHAIN_FOR_PRIMARY_TARGET would not be needed.
This detail should only (positively) affect users invoking "make
check" in sim/ instead of "make check-sim" (or "make check") at the
toplevel.  Now the output from "configure" matches the target tools
actually used by sim at test-time, for the "primary target".

Using $(CC) for "example-" targets CC_FOR_TARGET is not changed, as
that appears to be a deliberate special-case.

Note that all tools still have to be installed and present in
$PATH at configure-time to be properly used at test-time.

sim:
	* m4/sim_ac_toolchain.m4 (SIM_AC_CHECK_TOOLCHAIN_FOR_PRIMARY_TARGET):
	New defun.
	(SIM_TOOLCHAIN_VARS): Call it using AC_REQUIRE, and use variables
	AS_FOR_TARGET, LD_FOR_TARGET and CC_FOR_TARGET instead of hard-coded
	values.
	* Makefile.in, configure: Regenerate.

1 files changed, 5 insertions, 2 deletions

diff --git a/sim/Makefile.in b/sim/Makefile.in
index 8b208e0..49a3c0b 100644
--- a/sim/Makefile.in
+++ b/sim/Makefile.in
@@ -1,7 +1,7 @@
 # Makefile.in generated by automake 1.15.1 from Makefile.am.
 # @configure_input@
 
-# Copyright (C) 1994-2022 Free Software Foundation, Inc.
+# Copyright (C) 1994-2017 Free Software Foundation, Inc.
 
 # This Makefile.in is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -14,7 +14,7 @@
 
 @SET_MAKE@
 
-#   Copyright (C) 1993-2021 Free Software Foundation, Inc.
+#   Copyright (C) 1993-2022 Free Software Foundation, Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -652,6 +652,7 @@ AMTAR = @AMTAR@
 AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
 AR = @AR@
 AR_FOR_BUILD = @AR_FOR_BUILD@
+AS_FOR_TARGET = @AS_FOR_TARGET@
 AS_FOR_TARGET_AARCH64 = @AS_FOR_TARGET_AARCH64@
 AS_FOR_TARGET_ARM = @AS_FOR_TARGET_ARM@
 AS_FOR_TARGET_AVR = @AS_FOR_TARGET_AVR@
@@ -693,6 +694,7 @@ CATOBJEXT = @CATOBJEXT@
 CC = @CC@
 CCDEPMODE = @CCDEPMODE@
 CC_FOR_BUILD = @CC_FOR_BUILD@
+CC_FOR_TARGET = @CC_FOR_TARGET@
 CC_FOR_TARGET_AARCH64 = @CC_FOR_TARGET_AARCH64@
 CC_FOR_TARGET_ARM = @CC_FOR_TARGET_ARM@
 CC_FOR_TARGET_AVR = @CC_FOR_TARGET_AVR@
@@ -757,6 +759,7 @@ INSTOBJEXT = @INSTOBJEXT@
 LD = @LD@
 LDFLAGS = @LDFLAGS@
 LDFLAGS_FOR_BUILD = @LDFLAGS_FOR_BUILD@
+LD_FOR_TARGET = @LD_FOR_TARGET@
 LD_FOR_TARGET_AARCH64 = @LD_FOR_TARGET_AARCH64@
 LD_FOR_TARGET_ARM = @LD_FOR_TARGET_ARM@
 LD_FOR_TARGET_AVR = @LD_FOR_TARGET_AVR@