gcc/:
	PR c/37303
	* c-decl.c (build_compound_literal): Make the decl readonly if it
	an array of a readonly type.
	* gimplify.c (gimplify_compound_literal_expr): Add fallback
	parameter.  Change all callers.  If the decl is not addressable
	and is not an l-value, make it readonly.
gcc/testsuite:
	PR c/37303
	* gcc.dg/pr37303.c: New test.

From-SVN: r187027