Similar to commit fb5d27be27
"libgomp: Consider '--with-build-sysroot=[...]' for target libraries' build-tree testing (instead of build-time 'CC' etc.) [PR91884, PR109951]",
this is commit a0b48358cb
"libffi/test: Fix compilation for build sysroot" done differently,
avoiding build-tree testing use of any random gunk that may appear in
build-time 'CC', 'CXX'.
PR testsuite/109951
libffi/
* configure.ac: 'AC_SUBST(SYSROOT_CFLAGS_FOR_TARGET)'.
<local.exp>: Don't set 'CC_FOR_TARGET', 'CXX_FOR_TARGET', instead
set 'SYSROOT_CFLAGS_FOR_TARGET'.
* Makefile.in: Regenerate.
* configure: Likewise.
* include/Makefile.in: Likewise.
* man/Makefile.in: Likewise.
* testsuite/Makefile.in: Likewise.
* testsuite/lib/libffi.exp (libffi_target_compile): If
'--with-build-sysroot=[...]' was specified, use it for build-tree
testing.
967d4171b2