Adds Simulator Longjmp and enables many tests for arm64.

runtime/vm/stub_code_arm64.cc

Index: runtime/vm/stub_code_arm64.cc
===================================================================
--- runtime/vm/stub_code_arm64.cc	(revision 35592)
+++ runtime/vm/stub_code_arm64.cc	(working copy)
@@ -152,7 +152,8 @@
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(SP, R0, Isolate::top_exit_frame_info_offset());
+  __ mov(TMP, SP);
+  __ StoreToOffset(TMP, R0, Isolate::top_exit_frame_info_offset());
 
   // Save current Context pointer into Isolate structure.
   __ StoreToOffset(CTX, R0, Isolate::top_context_offset());
@@ -236,8 +237,7 @@
   __ StoreToOffset(R2, CTX, Isolate::vm_tag_offset());
 
   // Reset exit frame information in Isolate structure.
-  __ LoadImmediate(R2, 0, kNoPP);
-  __ StoreToOffset(R2, CTX, Isolate::top_exit_frame_info_offset());
+  __ StoreToOffset(ZR, CTX, Isolate::top_exit_frame_info_offset());
 
   // Load Context pointer from Isolate structure into R2.
   __ LoadFromOffset(R2, CTX, Isolate::top_context_offset());
@@ -336,8 +336,7 @@
   __ StoreToOffset(R2, CTX, Isolate::vm_tag_offset());
 
   // Reset exit frame information in Isolate structure.
-  __ LoadImmediate(R2, 0, kNoPP);
-  __ StoreToOffset(R2, CTX, Isolate::top_exit_frame_info_offset());
+  __ StoreToOffset(ZR, CTX, Isolate::top_exit_frame_info_offset());
 
   // Load Context pointer from Isolate structure into R2.
   __ LoadFromOffset(R2, CTX, Isolate::top_context_offset());