testsuite: Require fsanitize support on the target.

	* g++.dg/warn/uninit-pr93100.C: Require fsantize support.

gcc/testsuite/g++.dg/warn/uninit-pr93100.C

 /* PR tree-optimization/98508 - Sanitizer disable -Wall and -Wextra
    { dg-do compile }
+   { dg-require-effective-target no_fsanitize_address }
    { dg-options "-O0 -Wall -fsanitize=address" } */
 
 struct S