Save/restore only live registers in the generator suspend/resume.

src/interpreter/bytecode-register-optimizer.h

Index: src/interpreter/bytecode-register-optimizer.h
diff --git a/src/interpreter/bytecode-register-optimizer.h b/src/interpreter/bytecode-register-optimizer.h
index 494abb6c96c9e8b7fec2fe5beb530d86cb675f8f..e73e89a4083afecf77cf357e7ece1bf8c6e9ab0b 100644
--- a/src/interpreter/bytecode-register-optimizer.h
+++ b/src/interpreter/bytecode-register-optimizer.h
@@ -67,7 +67,8 @@ class V8_EXPORT_PRIVATE BytecodeRegisterOptimizer final
     if (Bytecodes::IsJump(bytecode) || Bytecodes::IsSwitch(bytecode) ||
         bytecode == Bytecode::kDebugger ||
         bytecode == Bytecode::kSuspendGenerator ||
-        bytecode == Bytecode::kResumeGenerator) {
+        bytecode == Bytecode::kResumeGenerator ||

[rmcilroy, 2017/06/01 10:44:44]

Remove ResumeGenerator from here now.

[Jarin, 2017/06/01 12:48:22]

Done.

+        bytecode == Bytecode::kRestoreGeneratorRegisters) {
       // All state must be flushed before emitting
       // - a jump bytecode (as the register equivalents at the jump target
       //   aren't known)