PPC/s390: Fix register mapping and imm16 issue

src/full-codegen/ppc/full-codegen-ppc.cc

Index: src/full-codegen/ppc/full-codegen-ppc.cc
diff --git a/src/full-codegen/ppc/full-codegen-ppc.cc b/src/full-codegen/ppc/full-codegen-ppc.cc
index b456ab078be7b56b9b2259b2ce3f59f68268e986..51f5ff896839f15beebb2b6dce81dd516c7e250a 100644
--- a/src/full-codegen/ppc/full-codegen-ppc.cc
+++ b/src/full-codegen/ppc/full-codegen-ppc.cc
@@ -1833,7 +1833,8 @@ void FullCodeGenerator::EmitOperandStackDepthCheck() {
     int expected_diff = StandardFrameConstants::kFixedFrameSizeFromFp +
                         operand_stack_depth_ * kPointerSize;
     __ sub(r3, fp, sp);
-    __ cmpi(r3, Operand(expected_diff));
+    __ mov(ip, Operand(expected_diff));
+    __ cmp(r3, ip);
     __ Assert(eq, kUnexpectedStackDepth);
   }
 }