Implements a new API to set a function entry hook for profiling.

src/arm/full-codegen-arm.cc

Index: src/arm/full-codegen-arm.cc
diff --git a/src/arm/full-codegen-arm.cc b/src/arm/full-codegen-arm.cc
index 33a22f1c8a788d1c441bc316a1980aab67740167..c97131cff510d8512c57ebe211dc6c869685d3b2 100644
--- a/src/arm/full-codegen-arm.cc
+++ b/src/arm/full-codegen-arm.cc
@@ -141,6 +141,14 @@ void FullCodeGenerator::Generate() {
   }
 #endif
 
+  const FunctionEntryHook* hook_location = V8::GetFunctionEntryHookLocation();
+  if (*hook_location != NULL) {
+    ProfileEntryHookStub stub;
+    __ push(lr);
+    __ CallStub(&stub);
+    __ pop(lr);
+  }
+
   // Strict mode functions and builtins need to replace the receiver
   // with undefined when called as functions (without an explicit
   // receiver object). r5 is zero for method calls and non-zero for