Revert "VM(RegExp): Allow OSR optimization of RegExp :matcher functions."

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
diff --git a/runtime/vm/intermediate_language.cc b/runtime/vm/intermediate_language.cc
index c1520e6b20843b40615e2644813f7adc2a40d02f..cfb7622d3a7f58b48206093d101e2b65f94acd93 100644
--- a/runtime/vm/intermediate_language.cc
+++ b/runtime/vm/intermediate_language.cc
@@ -2066,17 +2066,6 @@ Definition* RedefinitionInstr::Canonicalize(FlowGraph* flow_graph) {
 }
 
 
-Instruction* CheckStackOverflowInstr::Canonicalize(FlowGraph* flow_graph) {
-  switch (kind_) {
-    case kOsrAndPreemption:
-      return this;
-    case kOsrOnly:
-      // Don't need OSR entries in the optimized code.
-      return NULL;
-  }
-}
-
-
 bool LoadFieldInstr::IsImmutableLengthLoad() const {
   switch (recognized_kind()) {
     case MethodRecognizer::kObjectArrayLength: