Enables simple static call test on arm64.

runtime/vm/assembler_arm64.h

Index: runtime/vm/assembler_arm64.h
===================================================================
--- runtime/vm/assembler_arm64.h	(revision 35373)
+++ runtime/vm/assembler_arm64.h	(working copy)
@@ -525,9 +525,10 @@
   }
 
   // Loads and Stores.
-  void ldr(Register rt, Address a) {
+  void ldr(Register rt, Address a, OperandSize sz = kDoubleWord) {
     if (a.type() == Address::PCOffset) {
-      EmitLoadRegLiteral(LDRpc, rt, a, kDoubleWord);
+      ASSERT(sz == kDoubleWord);
+      EmitLoadRegLiteral(LDRpc, rt, a, sz);
     } else {
       // If we are doing pre-/post-indexing, and the base and result registers
       // are the same, then the result of the load will be clobbered by the
@@ -535,11 +536,11 @@
       ASSERT(((a.type() != Address::PreIndex) &&
               (a.type() != Address::PostIndex)) ||
              (rt != a.base()));
-      EmitLoadStoreReg(LDR, rt, a, kDoubleWord);
+      EmitLoadStoreReg(LDR, rt, a, sz);
     }
   }
-  void str(Register rt, Address a) {
-    EmitLoadStoreReg(STR, rt, a, kDoubleWord);
+  void str(Register rt, Address a, OperandSize sz = kDoubleWord) {
+    EmitLoadStoreReg(STR, rt, a, sz);
   }
 
   // Comparison.
@@ -684,11 +685,15 @@
   // PP should be passed for pp.
   void AddImmediate(Register dest, Register rn, int64_t imm, Register pp);
   void CompareImmediate(Register rn, int64_t imm, Register pp);
-  void LoadFromOffset(Register dest, Register base, int32_t offset);
+
+  void LoadFromOffset(Register dest, Register base, int32_t offset,
+                      OperandSize sz = kDoubleWord);
   void LoadFieldFromOffset(Register dest, Register base, int32_t offset) {
     LoadFromOffset(dest, base, offset - kHeapObjectTag);
   }
-  void StoreToOffset(Register dest, Register base, int32_t offset);
+
+  void StoreToOffset(Register dest, Register base, int32_t offset,
+                     OperandSize sz = kDoubleWord);
   void StoreFieldToOffset(Register dest, Register base, int32_t offset) {
     StoreToOffset(dest, base, offset - kHeapObjectTag);
   }
@@ -742,9 +747,13 @@
 
   void EnterCallRuntimeFrame(intptr_t frame_size);
   void LeaveCallRuntimeFrame();
-
   void CallRuntime(const RuntimeEntry& entry, intptr_t argument_count);
 
+  // Set up a stub frame so that the stack traversal code can easily identify
+  // a stub frame.
+  void EnterStubFrame(bool load_pp = false);
+  void LeaveStubFrame();
+
  private:
   AssemblerBuffer buffer_;  // Contains position independent code.