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

src/regexp-macro-assembler-tracer.cc

Index: src/regexp-macro-assembler-tracer.cc
===================================================================
--- src/regexp-macro-assembler-tracer.cc	(revision 1094)
+++ src/regexp-macro-assembler-tracer.cc	(working copy)
@@ -210,6 +210,12 @@
 }
 
 
+void RegExpMacroAssemblerTracer::CheckAtStart(Label* on_at_start) {
+  PrintF(" CheckAtStart(label[%08x]);\n", on_at_start);
+  assembler_->CheckAtStart(on_at_start);
+}
+
+
 void RegExpMacroAssemblerTracer::CheckNotAtStart(Label* on_not_at_start) {
   PrintF(" CheckNotAtStart(label[%08x]);\n", on_not_at_start);
   assembler_->CheckNotAtStart(on_not_at_start);