gcc/ChangeLog:

	PR c/86453
	* attribs.c (decl_attributes): Reject conflicting attributes before
	calling attribute handlers.

gcc/testsuite/ChangeLog:

	PR c/86453
	* c-c++-common/Wattributes.c: Adjust.
	* gcc.dg/Wattributes-10.c: New test.
	* g++.dg/Wattributes-3.C: Adjust.
	* gcc.dg/Wattributes-6.c: Adjust.
	* gcc.dg/pr18079.c: Adjust.
	* gcc.dg/torture/pr42363.c: Adjust.

From-SVN: r262596