PPC/s390: [wasm] Fix explicit stack check to be Isolate independent.

Port 4c4c3437

Original Commit Message:

    This fixes the special stack check we emit for very large frames to no
    longer embed the limit address but load it from the instance object
    instead. It makes sure WasmCode remains independent of the Isolate.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:7424
LOG=N

Change-Id: I35e662ee89fbad679a6c103518e4d1feb2c8dce0
Reviewed-on: https://chromium-review.googlesource.com/1131996Reviewed-by: Muntasir Mallick <mmallick@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#54368}

src/compiler/ppc/code-generator-ppc.cc

@@ -2365,8 +2365,9 @@ void CodeGenerator::AssembleConstructFrame() {
       // check in the condition code.
       if ((shrink_slots * kPointerSize) < (FLAG_stack_size * 1024)) {
         Register scratch = ip;
-        __ Move(scratch,
-                ExternalReference::address_of_real_stack_limit(__ isolate()));
+        __ LoadP(scratch, FieldMemOperand(
+                            kWasmInstanceRegister,
+                            WasmInstanceObject::kRealStackLimitAddressOffset));
         __ LoadP(scratch, MemOperand(scratch), r0);
         __ Add(scratch, scratch, shrink_slots * kPointerSize, r0);
         __ cmpl(sp, scratch);

src/compiler/s390/code-generator-s390.cc

@@ -3005,8 +3005,9 @@ void CodeGenerator::AssembleConstructFrame() {
       // check in the condition code.
       if ((shrink_slots * kPointerSize) < (FLAG_stack_size * 1024)) {
         Register scratch = r1;
-        __ Move(scratch,
-                ExternalReference::address_of_real_stack_limit(__ isolate()));
+        __ LoadP(scratch, FieldMemOperand(
+                            kWasmInstanceRegister,
+                            WasmInstanceObject::kRealStackLimitAddressOffset));
         __ LoadP(scratch, MemOperand(scratch));
         __ AddP(scratch, scratch, Operand(shrink_slots * kPointerSize));
         __ CmpLogicalP(sp, scratch);