Add support for lazy deoptimization from deferred stack checks

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 24e2044f27417b9c17c2297a6e80ebfc95df3ba6..a947cb8234df23de6889f7fc0f74cd1accbc9bf8 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -257,11 +257,28 @@ LInstruction* LCodeGen::GetNextInstruction() {
 
 bool LCodeGen::GenerateDeferredCode() {
   ASSERT(is_generating());
-  for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
-    LDeferredCode* code = deferred_[i];
-    __ bind(code->entry());
-    code->Generate();
-    __ jmp(code->exit());
+  Label last_jump;
+  if (deferred_.length() > 0) {
+    for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
+      LDeferredCode* code = deferred_[i];
+      __ bind(code->entry());
+      code->Generate();
+#ifdef DEBUG
+      if (i == deferred_.length() - 1) {
+        __ bind(&last_jump);
+      }
+#endif
+      __ jmp(code->exit());
+    }
+
+    // Reserve some space to ensure that the last piece of deferred code
+    // have room for lazy bailout.
+    __ nop();
+    __ nop();
+
+    int code_generated =
+        masm_->InstructionsGeneratedSince(&last_jump) * Assembler::kInstrSize;
+    ASSERT(Deoptimizer::patch_size() <= code_generated);
   }
 
   // Force constant pool emission at the end of the deferred code to make
@@ -4322,8 +4339,16 @@ void LCodeGen::DoIn(LIn* instr) {
 
 
 void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
-  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
-  CallRuntimeFromDeferred(Runtime::kStackGuard, 0, instr);
+  {
+    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
+    __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
+    RegisterLazyDeoptimization(
+        instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
+  }
+
+  // The gap code includes the restoring of the safepoint registers.
+  int pc = masm()->pc_offset();
+  safepoints_.SetPcAfterGap(pc);
 }