[debugger] fix break locations for assignments and return.

test/cctest/cctest.status

Index: test/cctest/cctest.status
diff --git a/test/cctest/cctest.status b/test/cctest/cctest.status
index a5ab993fbd62d1591134def1a3d972ec1b4e1fe0..69ec33f20948d9b49195c8dc1fef3cbe8a547977 100644
--- a/test/cctest/cctest.status
+++ b/test/cctest/cctest.status
@@ -502,15 +502,12 @@
 ##############################################################################
 ['ignition == True', {
   # TODO(yangguo,4690): Test failures in debugger tests.
-  'test-debug/DebugStepLocals': [FAIL],
   'test-debug/DebugStepKeyedLoadLoop': [FAIL],
   'test-debug/DebugStepKeyedStoreLoop': [FAIL],
   'test-debug/DebugStepIf': [FAIL],
   'test-debug/DebugStepNamedLoadLoop': [FAIL],
-  'test-debug/DebugStepDeclarations': [FAIL],
   'test-debug/BreakPointConstructCallWithGC': [PASS, FAIL],
   'test-debug/DebugStepNamedStoreLoop': [FAIL],
-  'test-debug/DebugStepLinearMixedICs': [FAIL],
   'test-debug/DebugStepSwitch': [FAIL],
   'test-debug/DebugStepWhile': [FAIL],
   'test-debug/DebugStepFor': [FAIL],