Check for empty repetitions.

src/regexp-macro-assembler-tracer.cc

Index: src/regexp-macro-assembler-tracer.cc
diff --git a/src/regexp-macro-assembler-tracer.cc b/src/regexp-macro-assembler-tracer.cc
index 94ede519d1f13b5a74ac5cf40dc821c1e537b86b..2eb7ec58f3e9f51e5549b2bd0e1222005b7b024e 100644
--- a/src/regexp-macro-assembler-tracer.cc
+++ b/src/regexp-macro-assembler-tracer.cc
@@ -373,6 +373,14 @@ void RegExpMacroAssemblerTracer::IfRegisterLT(int register_index,
 }
 
 
+void RegExpMacroAssemblerTracer::IfRegisterEqPos(int register_index,
+                                                 Label* if_eq) {
+  PrintF(" IfRegisterEqPos(register=%d, label[%08x]);\n",
+         register_index, if_eq);
+  assembler_->IfRegisterEqPos(register_index, if_eq);
+}
+
+
 void RegExpMacroAssemblerTracer::IfRegisterGE(int register_index,
                                               int comparand, Label* if_ge) {
   PrintF(" IfRegisterGE(register=%d, number=%d, label[%08x]);\n",