Revert "Implement rewind: drop one or more frames from the debugger."

runtime/vm/stub_code_ia32.cc

Index: runtime/vm/stub_code_ia32.cc
diff --git a/runtime/vm/stub_code_ia32.cc b/runtime/vm/stub_code_ia32.cc
index ce6521d339ddb381173946cb60d402c2210b8d9d..ca70617824bf92fbfc39004256c45e44bdd276ba 100644
--- a/runtime/vm/stub_code_ia32.cc
+++ b/runtime/vm/stub_code_ia32.cc
@@ -351,6 +351,8 @@ static void PushArgumentsArray(Assembler* assembler) {
 //   +------------------+
 //   | return-address   |  (deoptimization point)
 //   +------------------+
+//   | Saved CODE_REG   |
+//   +------------------+
 //   | ...              | <- SP of optimized frame
 //
 // Parts of the code cannot GC, part of the code can GC.
@@ -460,16 +462,15 @@ static void GenerateDeoptimizationSequence(Assembler* assembler,
   __ popl(ECX);       // Pop return address.
   __ addl(ESP, EBX);  // Remove materialization arguments.
   __ pushl(ECX);      // Push return address.
-  // The caller is responsible for emitting the return instruction.
+  __ ret();
 }
 
 
 // EAX: result, must be preserved
 void StubCode::GenerateDeoptimizeLazyFromReturnStub(Assembler* assembler) {
   // Return address for "call" to deopt stub.
-  __ pushl(Immediate(kZapReturnAddress));
+  __ pushl(Immediate(0xe1e1e1e1));
   GenerateDeoptimizationSequence(assembler, kLazyDeoptFromReturn);
-  __ ret();
 }
 
 
@@ -477,15 +478,13 @@ void StubCode::GenerateDeoptimizeLazyFromReturnStub(Assembler* assembler) {
 // EDX: stacktrace, must be preserved
 void StubCode::GenerateDeoptimizeLazyFromThrowStub(Assembler* assembler) {
   // Return address for "call" to deopt stub.
-  __ pushl(Immediate(kZapReturnAddress));
+  __ pushl(Immediate(0xe1e1e1e1));
   GenerateDeoptimizationSequence(assembler, kLazyDeoptFromThrow);
-  __ ret();
 }
 
 
 void StubCode::GenerateDeoptimizeStub(Assembler* assembler) {
   GenerateDeoptimizationSequence(assembler, kEagerDeopt);
-  __ ret();
 }
 
 
@@ -1836,22 +1835,6 @@ void StubCode::GenerateRunExceptionHandlerStub(Assembler* assembler) {
 }
 
 
-// Deoptimize a frame on the call stack before rewinding.
-// The arguments are stored in the Thread object.
-// No result.
-void StubCode::GenerateDeoptForRewindStub(Assembler* assembler) {
-  // Push the deopt pc.
-  __ pushl(Address(THR, Thread::resume_pc_offset()));
-  GenerateDeoptimizationSequence(assembler, kEagerDeopt);
-
-  // After we have deoptimized, jump to the correct frame.
-  __ EnterStubFrame();
-  __ CallRuntime(kRewindPostDeoptRuntimeEntry, 0);
-  __ LeaveFrame();
-  __ int3();
-}
-
-
 // Calls to the runtime to optimize the given function.
 // EBX: function to be reoptimized.
 // EDX: argument descriptor (preserved).