Merge stack usage reduction for overflow checks

Cherry pick from: b038ba66a166fb264ca121632f447712e0973b5b

Change-Id: I19999e72ff731d4fc73d91b9ff767de5858c15ee
diff --git a/runtime/thread.h b/runtime/thread.h
index 120ff6f..fe950c4 100644
--- a/runtime/thread.h
+++ b/runtime/thread.h
@@ -594,16 +594,10 @@
   void SetStackEndForStackOverflow() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Set the stack end to that to be used during regular execution
-  void ResetDefaultStackEnd(bool implicit_overflow_check) {
+  void ResetDefaultStackEnd() {
     // Our stacks grow down, so we want stack_end_ to be near there, but reserving enough room
     // to throw a StackOverflowError.
-    if (implicit_overflow_check) {
-      // For implicit checks we also need to add in the protected region above the
-      // overflow region.
-      tlsPtr_.stack_end = tlsPtr_.stack_begin + kStackOverflowImplicitCheckSize;
-    } else {
-      tlsPtr_.stack_end = tlsPtr_.stack_begin + GetStackOverflowReservedBytes(kRuntimeISA);
-    }
+    tlsPtr_.stack_end = tlsPtr_.stack_begin + GetStackOverflowReservedBytes(kRuntimeISA);
   }
 
   // Install the protected region for implicit stack checks.