Throw a more descriptive exception when blocking 'eval' via CSP.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 4ce2e1ed5c446cc58b49e94c17cfa295473715ab..408300c9937590aa7ef2f10c40b4f9e5e24eedd2 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -9100,8 +9100,10 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_CompileString) {
   // strings. Throw an exception if it doesn't.
   if (context->allow_code_gen_from_strings()->IsFalse() &&
       !CodeGenerationFromStringsAllowed(isolate, context)) {
-    return isolate->Throw(*isolate->factory()->NewError(
-        "code_gen_from_strings", HandleVector<Object>(NULL, 0)));
+    Handle<Object> error_message =
+        context->ErrorMessageForCodeGenerationFromStrings();
+    return isolate->Throw(*isolate->factory()->NewEvalError(
+        "code_gen_from_strings", HandleVector<Object>(&error_message, 1)));
   }
 
   // Compile source string in the native context.
@@ -9128,8 +9130,10 @@ static ObjectPair CompileGlobalEval(Isolate* isolate,
   // strings. Throw an exception if it doesn't.
   if (native_context->allow_code_gen_from_strings()->IsFalse() &&
       !CodeGenerationFromStringsAllowed(isolate, native_context)) {
-    isolate->Throw(*isolate->factory()->NewError(
-        "code_gen_from_strings", HandleVector<Object>(NULL, 0)));
+    Handle<Object> error_message =
+        context->ErrorMessageForCodeGenerationFromStrings();
+    isolate->Throw(*isolate->factory()->NewEvalError(
+        "code_gen_from_strings", HandleVector<Object>(&error_message, 1)));
     return MakePair(Failure::Exception(), NULL);
   }