PR target/77728

PR target/77728
	* config/arm/arm.c: Include gimple.h.
	(aapcs_layout_arg): Emit -Wpsabi note if arm_needs_doubleword_align
	returns negative, increment ncrn only if it returned positive.
	(arm_needs_doubleword_align): Return int instead of bool,
	ignore DECL_ALIGN of non-FIELD_DECL TYPE_FIELDS chain
	members, but if there is any such non-FIELD_DECL
	> PARM_BOUNDARY aligned decl, return -1 instead of false.
	(arm_function_arg): Emit -Wpsabi note if arm_needs_doubleword_align
	returns negative, increment nregs only if it returned positive.
	(arm_setup_incoming_varargs): Likewise.
	(arm_function_arg_boundary): Emit -Wpsabi note if
	arm_needs_doubleword_align returns negative, return
	DOUBLEWORD_ALIGNMENT only if it returned positive.
testsuite/
	* g++.dg/abi/pr77728-1.C: New test.

	Backported from trunk:
	0e6ba620ce829dbde3ece9cefdbe09355ddfbb74

Change-Id: Ia454a63c3ebb930e546188ded5f339a967d81754
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-7-branch@247259 138bc75d-0d04-0410-961f-82ee72b054a4