ARM: correctly calculate the offset of FP in its push.

When we folded the DPR alignment gap into a push, we weren't noting the extra
distance from the beginning of the push to the FP, and so FP ended up pointing
at an incorrect offset.

The .cfi_def_cfa_offset directives are still wrong in this case, but I think
that can be improved by refactoring.

llvm-svn: 222056
diff --git a/llvm/test/CodeGen/ARM/dwarf-unwind.ll b/llvm/test/CodeGen/ARM/dwarf-unwind.ll
index 58f486d..0359e4b 100644
--- a/llvm/test/CodeGen/ARM/dwarf-unwind.ll
+++ b/llvm/test/CodeGen/ARM/dwarf-unwind.ll
@@ -66,3 +66,12 @@
   call void @bar()
   ret void
 }
+
+define void @test_frame_pointer_offset() minsize "no-frame-pointer-elim"="true" {
+; CHECK-LABEL: test_frame_pointer_offset:
+; CHECK: push.w {r3, r4, r5, r6, r7, r8, r9, r10, r11, lr}
+; CHECK: add r7, sp, #16
+  call void asm sideeffect "", "~{r4},~{r5},~{r6},~{r7},~{r8},~{r9},~{r10},~{r11},~{d8}"()
+  call void @bar()
+  ret void
+}
\ No newline at end of file