PPC/s390: Explicitly store the code layout in CodeDesc

Port ad3546ab

Original Commit Message:

    This is an initial step towards clarifying the layout of the
    instruction area. As follow-ups, we should remove additional
    safepoint and handler table offset parameters, and perhaps alter
    Code::safepoint_table_offset (handler_table) semantics to always
    contain a real offset and avoid the magic 0 signifying nonexistent
    tables.

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

Change-Id: I6c2d3244710f8f3f33bcceb3988e19547f55fba0
Reviewed-on: https://chromium-review.googlesource.com/c/1446138Reviewed-by: Milad Farazmand <miladfar@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#59218}

src/ppc/assembler-ppc.h

@@ -55,6 +55,8 @@
 namespace v8 {
 namespace internal {
 
+class SafepointTableBuilder;
+
 // -----------------------------------------------------------------------------
 // Machine instruction Operands
 
@@ -187,10 +189,17 @@ class Assembler : public AssemblerBase {
 
   virtual ~Assembler() {}
 
-  // GetCode emits any pending (non-emitted) code and fills the descriptor
-  // desc. GetCode() is idempotent; it returns the same result if no other
-  // Assembler functions are invoked in between GetCode() calls.
-  void GetCode(Isolate* isolate, CodeDesc* desc);
+  // GetCode emits any pending (non-emitted) code and fills the descriptor desc.
+  static constexpr int kNoHandlerTable = 0;
+  static constexpr SafepointTableBuilder* kNoSafepointTable = nullptr;
+  void GetCode(Isolate* isolate, CodeDesc* desc,
+               SafepointTableBuilder* safepoint_table_builder,
+               int handler_table_offset);
+
+  // Convenience wrapper for code without safepoint or handler tables.
+  void GetCode(Isolate* isolate, CodeDesc* desc) {
+    GetCode(isolate, desc, kNoSafepointTable, kNoHandlerTable);
+  }
 
   // Label operations & relative jumps (PPUM Appendix D)
   //

src/s390/assembler-s390.h

@@ -81,6 +81,8 @@
 namespace v8 {
 namespace internal {
 
+class SafepointTableBuilder;
+
 // -----------------------------------------------------------------------------
 // Machine instruction Operands
 
@@ -226,10 +228,17 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   virtual ~Assembler() {}
 
-  // GetCode emits any pending (non-emitted) code and fills the descriptor
-  // desc. GetCode() is idempotent; it returns the same result if no other
-  // Assembler functions are invoked in between GetCode() calls.
-  void GetCode(Isolate* isolate, CodeDesc* desc);
+  // GetCode emits any pending (non-emitted) code and fills the descriptor desc.
+  static constexpr int kNoHandlerTable = 0;
+  static constexpr SafepointTableBuilder* kNoSafepointTable = nullptr;
+  void GetCode(Isolate* isolate, CodeDesc* desc,
+               SafepointTableBuilder* safepoint_table_builder,
+               int handler_table_offset);
+
+  // Convenience wrapper for code without safepoint or handler tables.
+  void GetCode(Isolate* isolate, CodeDesc* desc) {
+    GetCode(isolate, desc, kNoSafepointTable, kNoHandlerTable);
+  }
 
   // Label operations & relative jumps (PPUM Appendix D)
   //