Add support for \b and ^ and $ in multiline mode, completing Irregexp...

src/regexp-macro-assembler-irregexp.cc

Index: src/regexp-macro-assembler-irregexp.cc
===================================================================
--- src/regexp-macro-assembler-irregexp.cc	(revision 1094)
+++ src/regexp-macro-assembler-irregexp.cc	(working copy)
@@ -256,6 +256,12 @@
 }
 
 
+void RegExpMacroAssemblerIrregexp::CheckAtStart(Label* on_at_start) {
+  Emit(BC_CHECK_AT_START);
+  EmitOrLink(on_at_start);
+}
+
+
 void RegExpMacroAssemblerIrregexp::CheckNotAtStart(Label* on_not_at_start) {
   Emit(BC_CHECK_NOT_AT_START);
   EmitOrLink(on_not_at_start);