S390: Fix Register conflict in CEntryStub

src/s390/code-stubs-s390.cc

Index: src/s390/code-stubs-s390.cc
diff --git a/src/s390/code-stubs-s390.cc b/src/s390/code-stubs-s390.cc
index 9358d31261dc5fe64c86fae4f33ec7ab8cfda764..b5a38e056fa55b9f789593df8741fd86aa7ff537 100644
--- a/src/s390/code-stubs-s390.cc
+++ b/src/s390/code-stubs-s390.cc
@@ -1104,9 +1104,9 @@ void CEntryStub::Generate(MacroAssembler* masm) {
     Label okay;
     ExternalReference pending_exception_address(
         Isolate::kPendingExceptionAddress, isolate());
-    __ mov(r4, Operand(pending_exception_address));
-    __ LoadP(r4, MemOperand(r4));
-    __ CompareRoot(r4, Heap::kTheHoleValueRootIndex);
+    __ mov(r1, Operand(pending_exception_address));
+    __ LoadP(r1, MemOperand(r1));
+    __ CompareRoot(r1, Heap::kTheHoleValueRootIndex);
     // Cannot use check here as it attempts to generate call into runtime.
     __ beq(&okay, Label::kNear);
     __ stop("Unexpected pending exception");