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

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index a7030ea910cfd7d41266d6585ea22f39f1d01315..cb50a2a0e0c7dfcea0aa311def2bf8184667eaff 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -7287,27 +7287,12 @@ class UnaryDoubleOpInstr : public TemplateDefinition<1, NoThrow, Pure> {
 
 class CheckStackOverflowInstr : public TemplateInstruction<0, NoThrow> {
  public:
-  enum Kind {
-    // kOsrAndPreemption stack overflow checks are emitted in both unoptimized
-    // and optimized versions of the code and they serve as both preemption and
-    // OSR entry points.
-    kOsrAndPreemption,
-
-    // kOsrOnly stack overflow checks are only needed in the unoptimized code
-    // because we can't OSR optimized code.
-    kOsrOnly,
-  };
-
   CheckStackOverflowInstr(TokenPosition token_pos,
                           intptr_t loop_depth,
-                          intptr_t deopt_id,
-                          Kind kind = kOsrAndPreemption)
+                          intptr_t deopt_id)
       : TemplateInstruction(deopt_id),
         token_pos_(token_pos),
-        loop_depth_(loop_depth),
-        kind_(kind) {
-    ASSERT(kind != kOsrOnly || loop_depth > 0);
-  }
+        loop_depth_(loop_depth) {}
 
   virtual TokenPosition token_pos() const { return token_pos_; }
   bool in_loop() const { return loop_depth_ > 0; }
@@ -7317,8 +7302,6 @@ class CheckStackOverflowInstr : public TemplateInstruction<0, NoThrow> {
 
   virtual bool ComputeCanDeoptimize() const { return true; }
 
-  virtual Instruction* Canonicalize(FlowGraph* flow_graph);
-
   virtual EffectSet Effects() const { return EffectSet::None(); }
 
   PRINT_OPERANDS_TO_SUPPORT
@@ -7326,7 +7309,6 @@ class CheckStackOverflowInstr : public TemplateInstruction<0, NoThrow> {
  private:
   const TokenPosition token_pos_;
   const intptr_t loop_depth_;
-  const Kind kind_;
 
   DISALLOW_COPY_AND_ASSIGN(CheckStackOverflowInstr);
 };