[PATCH][i386]Fix PR 57756

[Dominique Dhumieres]

> I see why pr57756.c could fail, if -msse4.2 is turned on by default. I
> think this test needs {dg-options "-mno-sse4.2"}.

This change allows the test to pass. The failure of gcc.target/i386/funcspec-5.c is

/opt/gcc/work/gcc/testsuite/gcc.target/i386/funcspec-5.c:34:1: warning: SSE instruction set disabled, using 387 arithmetics [enabled by default]
 extern void test_no_sse (void)   __attribute__((__target__("no-sse")));

This extra warning is silenced by dg-options "-mno-sse", but not by "-mno-sse4.2".

Dominique