8342409: [s390x] C1 unwind_handler fails to unlock synchronized methods with LM_MONITOR

Backport-of: 9201e9f

Author: offamitkumar

src/hotspot/cpu/s390/c1_LIRAssembler_s390.cpp

@@ -230,7 +230,11 @@ int LIR_Assembler::emit_unwind_handler() {
     LIR_Opr lock = FrameMap::as_opr(Z_R1_scratch);
     monitor_address(0, lock);
     stub = new MonitorExitStub(lock, true, 0);
-    __ unlock_object(Rtmp1, Rtmp2, lock->as_register(), *stub->entry());
+    if (LockingMode == LM_MONITOR) {
+      __ branch_optimized(Assembler::bcondAlways, *stub->entry());
+    } else {
+      __ unlock_object(Rtmp1, Rtmp2, lock->as_register(), *stub->entry());
+    }
     __ bind(*stub->continuation());
   }
 

src/hotspot/cpu/s390/c1_MacroAssembler_s390.cpp

@@ -119,6 +119,8 @@ void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox
     branch_optimized(Assembler::bcondNotZero, slow_case);
     // done
     bind(done);
+  } else {
+    assert(false, "Unhandled LockingMode:%d", LockingMode);
   }
 }
 
@@ -155,6 +157,8 @@ void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rb
     // If the object header was not pointing to the displaced header,
     // we do unlocking via runtime call.
     branch_optimized(Assembler::bcondNotEqual, slow_case);
+  } else {
+    assert(false, "Unhandled LockingMode:%d", LockingMode);
   }
   // done
   bind(done);