c-decl.c (grokdeclarator): Make error for duplicate type qualifiers into a pedwarn, disabled for C99.

	* c-decl.c (grokdeclarator): Make error for duplicate type
	qualifiers into a pedwarn, disabled for C99.

testsuite:
	* gcc.dg/c90-idem-qual-2.c, gcc.dg/c99-idem-qual-2.c: New tests.

From-SVN: r58983