Store FP instead of SP in the exit info when transitioning from Dart to C++.

runtime/vm/stub_code_arm64.cc

Index: runtime/vm/stub_code_arm64.cc
diff --git a/runtime/vm/stub_code_arm64.cc b/runtime/vm/stub_code_arm64.cc
index 745c8cd412cb3b461e679c4284b17ffd7e6896ef..f4c0842f094e43739e0ab3a23a3356b4fa27ca03 100644
--- a/runtime/vm/stub_code_arm64.cc
+++ b/runtime/vm/stub_code_arm64.cc
@@ -51,7 +51,7 @@ void StubCode::GenerateCallToRuntimeStub(Assembler* assembler) {
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to Dart VM C++ code.
-  __ StoreToOffset(SP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
+  __ StoreToOffset(FP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
 
 #if defined(DEBUG)
   { Label ok;
@@ -151,7 +151,7 @@ void StubCode::GenerateCallNativeCFunctionStub(Assembler* assembler) {
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(SP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
+  __ StoreToOffset(FP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
 
 #if defined(DEBUG)
   { Label ok;
@@ -253,7 +253,7 @@ void StubCode::GenerateCallBootstrapCFunctionStub(Assembler* assembler) {
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
-  __ StoreToOffset(SP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
+  __ StoreToOffset(FP, R28, Isolate::top_exit_frame_info_offset(), kNoPP);
 
 #if defined(DEBUG)
   { Label ok;