[turbofan] Assign appropriate types to RegExp builtins.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index fc2897d4b81930d5bb1979587ef8eb76b000a141..c60bdebe5148a3dd5dba1fbcb71f53a02526da19 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -7249,6 +7249,10 @@ class Script: public Struct {
   V(Function.prototype, apply, FunctionApply)               \
   V(Function.prototype, call, FunctionCall)                 \
   V(Object.prototype, hasOwnProperty, ObjectHasOwnProperty) \
+  V(RegExp.prototype, compile, RegExpCompile)               \
+  V(RegExp.prototype, exec, RegExpExec)                     \
+  V(RegExp.prototype, test, RegExpTest)                     \
+  V(RegExp.prototype, toString, RegExpToString)             \
   V(String.prototype, charCodeAt, StringCharCodeAt)         \
   V(String.prototype, charAt, StringCharAt)                 \
   V(String.prototype, concat, StringConcat)                 \