[regexp] Port RegExpExecStub to CSA (mostly)

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index fadc5011a81e8704c1430670d96d92c3345cf6e6..dc9e29431ac0ff676a9bb7c57290caf175f8a3e1 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -8599,16 +8599,6 @@ class JSRegExp: public JSObject {
 
   static const int kIrregexpDataSize = kIrregexpCaptureNameMapIndex + 1;
 
-  // Offsets directly into the data fixed array.
-  static const int kDataTagOffset =
-      FixedArray::kHeaderSize + kTagIndex * kPointerSize;
-  static const int kDataOneByteCodeOffset =
-      FixedArray::kHeaderSize + kIrregexpLatin1CodeIndex * kPointerSize;
-  static const int kDataUC16CodeOffset =
-      FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize;
-  static const int kIrregexpCaptureCountOffset =
-      FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize;
-
   // In-object fields.
   static const int kLastIndexFieldIndex = 0;
   static const int kInObjectFieldCount = 1;