MIPS: Allow specifying base offset when constructing Keyed hydrogen instructions.

Port r21426 (17e6338)

This is preparation for pending hydrogen stub work that needs to access memory using KeyedLoad/KeyedStore operations where the base offset used for the accesses are is the the default (e.g. the size of an FixedArray header for FixedArrays or zero for external arrays).

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/296983003

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21443 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.h

@@ -132,8 +132,7 @@ class LCodeGen: public LCodeGenBase {
                                  int constant_key,
                                  int element_size,
                                  int shift_size,
-                                 int additional_index,
-                                 int additional_offset);
+                                 int base_offset);
 
   // Emit frame translation commands for an environment.
   void WriteTranslation(LEnvironment* environment, Translation* translation);

src/mips/lithium-mips.cc

@@ -342,7 +342,7 @@ void LLoadKeyed::PrintDataTo(StringStream* stream) {
   stream->Add("[");
   key()->PrintTo(stream);
   if (hydrogen()->IsDehoisted()) {
-    stream->Add(" + %d]", additional_index());
+    stream->Add(" + %d]", base_offset());
   } else {
     stream->Add("]");
   }
@@ -354,7 +354,7 @@ void LStoreKeyed::PrintDataTo(StringStream* stream) {
   stream->Add("[");
   key()->PrintTo(stream);
   if (hydrogen()->IsDehoisted()) {
-    stream->Add(" + %d] <-", additional_index());
+    stream->Add(" + %d] <-", base_offset());
   } else {
     stream->Add("] <- ");
   }

src/mips/lithium-mips.h

@@ -1609,7 +1609,7 @@ class LLoadKeyed V8_FINAL : public LTemplateInstruction<1, 2, 0> {
   DECLARE_HYDROGEN_ACCESSOR(LoadKeyed)
 
   virtual void PrintDataTo(StringStream* stream);
-  uint32_t additional_index() const { return hydrogen()->index_offset(); }
+  uint32_t base_offset() const { return hydrogen()->base_offset(); }
 };
 
 
@@ -2178,7 +2178,7 @@ class LStoreKeyed V8_FINAL : public LTemplateInstruction<0, 3, 0> {
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
   bool NeedsCanonicalization() { return hydrogen()->NeedsCanonicalization(); }
-  uint32_t additional_index() const { return hydrogen()->index_offset(); }
+  uint32_t base_offset() const { return hydrogen()->base_offset(); }
 };