testsuite: i386: Fix gcc.target/i386/sse2-stv-1.c on Solaris/x86

gcc.target/i386/sse2-stv-1.c FAILs on 32-bit Solaris/x86:

FAIL: gcc.target/i386/sse2-stv-1.c scan-assembler-not %[er]sp
FAIL: gcc.target/i386/sse2-stv-1.c scan-assembler-not shldl

The test assumes the Linux/x86 default of -mno-stackrealign, while
32-bit Solaris/x86 default to -mstackrealign.

Fixed by explicitly specifying -mno-stackrealign.

Tested on i386-pc-solaris2.11 and i686-pc-linux-gnu.

2024-02-01  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc/testsuite:
	* gcc.target/i386/sse2-stv-1.c (dg-options): Add -mno-stackrealign.