re PR rtl-optimization/87600 (Fix for PRs 86939 and 87479 causes build issues for...

re PR rtl-optimization/87600 (Fix for PRs 86939 and 87479 causes build issues for several targets)

gcc/
	PR rtl-optimization/87600
	* cfgexpand.c (expand_asm_stmt): Catch illegal asm constraint usage.
	* lra-constraints.c (process_alt_operands): Skip illegal hard
	register usage.  Prefer reloading non hard register operands.

gcc/testsuite/
	PR rtl-optimization/87600
	* gcc.dg/pr87600.h: New file.
	* gcc.dg/pr87600-1.c: New test.
	* gcc.dg/pr87600-2.c: Likewise.

From-SVN: r265942