testsuite: i386: Restrict gcc.target/i386/fhardened-1.c etc. to Linux/GNU

testsuite: i386: Restrict gcc.target/i386/fhardened-1.c etc. to Linux/GNU

The new gcc.target/i386/fhardened-1.c etc. tests FAIL on Solaris/x86 and
Darwin/x86:

FAIL: gcc.target/i386/fhardened-1.c (test for excess errors)
FAIL: gcc.target/i386/fhardened-2.c (test for excess errors)

Excess errors:
cc1: warning: '-fhardened' not supported for this target

Support for -fhardened is restricted to HAVE_FHARDENED_SUPPORT in
toplev.cc (process_options) which again is only defined for linux*|gnu*
targets in gcc/configure.ac.

Accordingly, this patch restricts the tests to those two, as is already
done in gcc.target/i386/cf_check-6.c.

Tested on i386-pc-solaris2.11 and x86_64-pc-linux-gnu.

2024-04-15  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc/testsuite:
	* gcc.target/i386/fhardened-1.c: Restrict to Linux/GNU.
	* gcc.target/i386/fhardened-2.c: Likewise.