Require an isolate parameter for most external reference creation to

src/ia32/assembler-ia32.h

Index: src/ia32/assembler-ia32.h
diff --git a/src/ia32/assembler-ia32.h b/src/ia32/assembler-ia32.h
index 4bcc1ec764559a9c480661cd5bd3e2d9dbc9d85a..be1846ffc94c61294f79d0ae4868d9ac0d6aadbb 100644
--- a/src/ia32/assembler-ia32.h
+++ b/src/ia32/assembler-ia32.h
@@ -538,6 +538,9 @@ class Assembler : public Malloced {
   Assembler(void* buffer, int buffer_size);
   ~Assembler();
 
+  // Access the isolate with which the assembler is associated.
+  Isolate* isolate() { return isolate_; }
+
   // Overrides the default provided by FLAG_debug_code.
   void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
 
@@ -1010,7 +1013,8 @@ class Assembler : public Malloced {
   void emit_sse_operand(XMMRegister dst, XMMRegister src);
   void emit_sse_operand(Register dst, XMMRegister src);
 
-  byte* addr_at(int pos)  { return buffer_ + pos; }
+  byte* addr_at(int pos) { return buffer_ + pos; }
+
  private:
   byte byte_at(int pos)  { return buffer_[pos]; }
   void set_byte_at(int pos, byte value) { buffer_[pos] = value; }
@@ -1060,6 +1064,8 @@ class Assembler : public Malloced {
   friend class CodePatcher;
   friend class EnsureSpace;
 
+  Isolate* isolate_;
+
   // Code buffer:
   // The buffer into which code and relocation info are generated.
   byte* buffer_;