PPC/s390: [baseline] Fallback to handle references on heap compilation

Port 642a4673

Original Commit Message:

    If a GC happens between Code object allocation and Code finalization,
    we might have invalid embedded object references. We fallback and patch
    the refernces back to handles, then unbox the handles and relocate.

R=victorgomes@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: I680cc33fa9d06d7a00cc52c142599bb5536a9b88
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3060487Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#76004}

src/codegen/ppc/assembler-ppc.cc

@@ -1925,6 +1925,12 @@ bool Assembler::IsNop(Instr instr, int type) {
   return instr == (ORI | reg * B21 | reg * B16);
 }
 
+void Assembler::FixOnHeapReferences() {
+  // TODO(v8:11872) This function should never be called if Sparkplug on heap
+  // compilation is not supported.
+  UNREACHABLE();
+}
+
 void Assembler::GrowBuffer(int needed) {
   DCHECK_EQ(buffer_start_, buffer_->start());
 

src/codegen/ppc/assembler-ppc.h

@@ -196,6 +196,11 @@ class Assembler : public AssemblerBase {
     GetCode(isolate, desc, kNoSafepointTable, kNoHandlerTable);
   }
 
+  // This function is called when on-heap-compilation invariants are
+  // invalidated. For instance, when the assembler buffer grows or a GC happens
+  // between Code object allocation and Code object finalization.
+  void FixOnHeapReferences();
+
   void MaybeEmitOutOfLineConstantPool() { EmitConstantPool(); }
 
   inline void CheckTrampolinePoolQuick(int extra_space = 0) {

src/codegen/s390/assembler-s390.cc

@@ -750,6 +750,12 @@ void Assembler::dumy(int r1, int x2, int b2, int d2) {
 #endif
 }
 
+void Assembler::FixOnHeapReferences() {
+  // TODO(v8:11872) This function should never be called if Sparkplug on heap
+  // compilation is not supported.
+  UNREACHABLE();
+}
+
 void Assembler::GrowBuffer(int needed) {
   DCHECK_EQ(buffer_start_, buffer_->start());
 

src/codegen/s390/assembler-s390.h

@@ -241,6 +241,11 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     GetCode(isolate, desc, kNoSafepointTable, kNoHandlerTable);
   }
 
+  // This function is called when on-heap-compilation invariants are
+  // invalidated. For instance, when the assembler buffer grows or a GC happens
+  // between Code object allocation and Code object finalization.
+  void FixOnHeapReferences();
+
   // Unused on this architecture.
   void MaybeEmitOutOfLineConstantPool() {}