s390: [builtins] Add --stress-off-heap-code to test off-heap code

Port ca1d44e3

Original Commit Message:

    If enabled, this mode moves code for isolate-independent builtins off
    the JS heap at Isolate creation. The Code object itself is rewritten
    to tail-call the off-heap instruction stream.

R=jgruber@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Ia1b14663c17308101ce5e952fd508c891a098f8d
Reviewed-on: https://chromium-review.googlesource.com/899105Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#51077}

src/s390/macro-assembler-s390.cc

@@ -15,6 +15,7 @@
 #include "src/debug/debug.h"
 #include "src/external-reference-table.h"
 #include "src/frames-inl.h"
+#include "src/instruction-stream.h"
 #include "src/register-configuration.h"
 #include "src/runtime/runtime.h"
 
@@ -1522,7 +1523,7 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
 }
 
 void MacroAssembler::JumpToInstructionStream(const InstructionStream* stream) {
-  intptr_t bytes_address = static_cast<intptr_t>(stream->bytes());
+  intptr_t bytes_address = reinterpret_cast<intptr_t>(stream->bytes());
   mov(kOffHeapTrampolineRegister, Operand(bytes_address));
   Jump(kOffHeapTrampolineRegister);
 }