Make ScopedAssertNoThreadSuspension no overhead for non-debug

Previously it required Thread::Current() which may not be free.
The plan is to add a lot more ScopedAssertNoThreadSuspension in
the codebase.

Also cleaned up callers.

Bug: 31458474
Change-Id: I5a1621a5435476504d22266cc01a9bf26aab7568
diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index d03a9d8..1bf5c53 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -48,7 +48,7 @@
   // This method is being used by artQuickResolutionTrampoline, before it sets up
   // the passed parameters in a GC friendly way. Therefore we must never be
   // suspended while executing it.
-  ScopedAssertNoThreadSuspension sants(Thread::Current(), __FUNCTION__);
+  ScopedAssertNoThreadSuspension sants(__FUNCTION__);
 
   uint32_t method_index = inline_info.GetMethodIndexAtDepth(encoding, inlining_depth);
   InvokeType invoke_type = static_cast<InvokeType>(