Don't hardcode the location of the caller.

This is to avoid shooting ourselves in the foot when
dealing with inlined frames. Instead, use common methods
for fetching the caller and its dex pc.

Change-Id: I3467a7b50cf163022d332e80356f0aab747de252
diff --git a/runtime/arch/arm64/quick_entrypoints_arm64.S b/runtime/arch/arm64/quick_entrypoints_arm64.S
index f8b0734..6b16a2e5 100644
--- a/runtime/arch/arm64/quick_entrypoints_arm64.S
+++ b/runtime/arch/arm64/quick_entrypoints_arm64.S
@@ -459,8 +459,7 @@
     /*
      * All generated callsites for interface invokes and invocation slow paths will load arguments
      * as usual - except instead of loading arg0/x0 with the target Method*, arg0/x0 will contain
-     * the method_idx.  This wrapper will save arg1-arg3, load the caller's Method*, align the
-     * stack and call the appropriate C helper.
+     * the method_idx.  This wrapper will save arg1-arg3, and call the appropriate C helper.
      * NOTE: "this" is first visible argument of the target, and so can be found in arg1/x1.
      *
      * The helper will attempt to locate the target and return a 128-bit result in x0/x1 consisting
@@ -483,10 +482,9 @@
     // Helper signature is always
     // (method_idx, *this_object, *caller_method, *self, sp)
 
-    ldr    w2, [sp, #FRAME_SIZE_REFS_AND_ARGS_CALLEE_SAVE]  // pass caller Method*
-    mov    x3, xSELF                      // pass Thread::Current
-    mov    x4, sp
-    bl     \cxx_name                      // (method_idx, this, caller, Thread*, SP)
+    mov    x2, xSELF                      // pass Thread::Current
+    mov    x3, sp
+    bl     \cxx_name                      // (method_idx, this, Thread*, SP)
     mov    xIP0, x1                       // save Method*->code_
     RESTORE_REFS_AND_ARGS_CALLEE_SAVE_FRAME
     cbz    x0, 1f                         // did we find the target? if not go to exception delivery