Perform string add in generated code on IA-32 platforms...

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
===================================================================
--- src/ia32/macro-assembler-ia32.h	(revision 3397)
+++ src/ia32/macro-assembler-ia32.h	(working copy)
@@ -183,7 +183,7 @@
   // scratch can be passed as no_reg in which case an additional object
   // reference will be added to the reloc info. The returned pointers in result
   // and result_end have not yet been tagged as heap objects. If
-  // result_contains_top_on_entry is true the contnt of result is known to be
+  // result_contains_top_on_entry is true the content of result is known to be
   // the allocation top on entry (could be result_end from a previous call to
   // AllocateInNewSpace). If result_contains_top_on_entry is true scratch
   // should be no_reg as it is never used.
@@ -225,6 +225,32 @@
                           Register scratch2,
                           Label* gc_required);
 
+  // Allocate a sequential string. All the header fields of the string object
+  // are initialized.
+  void AllocateTwoByteString(Register result,
+                             Register length,
+                             Register scratch1,
+                             Register scratch2,
+                             Register scratch3,
+                             Label* gc_required);
+  void AllocateAsciiString(Register result,
+                           Register length,
+                           Register scratch1,
+                           Register scratch2,
+                           Register scratch3,
+                           Label* gc_required);
+
+  // Allocate a raw cons string object. Only the map field of the result is
+  // initialized.
+  void AllocateConsString(Register result,
+                          Register scratch1,
+                          Register scratch2,
+                          Label* gc_required);
+  void AllocateAsciiConsString(Register result,
+                               Register scratch1,
+                               Register scratch2,
+                               Label* gc_required);
+
   // ---------------------------------------------------------------------------
   // Support functions.
 
@@ -262,6 +288,9 @@
   // Call a code stub.
   void CallStub(CodeStub* stub);
 
+  // Tail call a code stub (jump).
+  void TailCallStub(CodeStub* stub);
+
   // Return from a code stub after popping its arguments.
   void StubReturn(int argc);