PR c/52181
	* c-decl.c (merge_decls): Copy DECL_USER_ALIGN bit from olddecl to
	newdecl.

	* decl.c (duplicate_decls): If olddecl has bigger DECL_ALIGN than
	newdecl, copy DECL_ALIGN to newdecl and or DECL_USER_ALIGN bits.

	* c-c++-common/pr52181.c: New test.

From-SVN: r184193