Implement flag and source getters on RegExp.prototype.

src/js/macros.py

Index: src/js/macros.py
diff --git a/src/js/macros.py b/src/js/macros.py
index f9bb12b705023c348d43a165c46b416aa2ec99d6..95b23a1443f036ad4b328a2889bf1c1ab1242e45 100644
--- a/src/js/macros.py
+++ b/src/js/macros.py
@@ -181,6 +181,14 @@ python macro CHAR_CODE(str) = ord(str[1]);
 define REGEXP_NUMBER_OF_CAPTURES = 0;
 define REGEXP_FIRST_CAPTURE = 3;
 
+# Macros for internal slot access.
+macro REGEXP_GLOBAL(regexp) = (regexp[regExpFlagsSymbol] & 1);
+macro REGEXP_IGNORE_CASE(regexp) = (regexp[regExpFlagsSymbol] & 2);
+macro REGEXP_MULTILINE(regexp) = (regexp[regExpFlagsSymbol] & 4);
+macro REGEXP_STICKY(regexp) = (regexp[regExpFlagsSymbol] & 8);
+macro REGEXP_UNICODE(regexp) = (regexp[regExpFlagsSymbol] & 16);
+macro REGEXP_SOURCE(regexp) = (regexp[regExpSourceSymbol]);
+
 # We can't put macros in macros so we use constants here.
 # REGEXP_NUMBER_OF_CAPTURES
 macro NUMBER_OF_CAPTURES(array) = ((array)[0]);