Improve error reporting for duplicate object template properties.

tools/generate-runtime-tests.py

Index: tools/generate-runtime-tests.py
diff --git a/tools/generate-runtime-tests.py b/tools/generate-runtime-tests.py
index f018cf044471eb3eb46470cff3536b64d5e9335b..c6049bf2be712ef8264dcc9581a860584f4d0768 100755
--- a/tools/generate-runtime-tests.py
+++ b/tools/generate-runtime-tests.py
@@ -47,8 +47,8 @@ EXPAND_MACROS = [
 # that the parser doesn't bit-rot. Change the values as needed when you add,
 # remove or change runtime functions, but make sure we don't lose our ability
 # to parse them!
-EXPECTED_FUNCTION_COUNT = 416
-EXPECTED_FUZZABLE_COUNT = 331
+EXPECTED_FUNCTION_COUNT = 417
+EXPECTED_FUZZABLE_COUNT = 332
 EXPECTED_CCTEST_COUNT = 6
 EXPECTED_UNKNOWN_COUNT = 4
 EXPECTED_BUILTINS_COUNT = 809
@@ -212,6 +212,7 @@ _NUMBER_FORMAT = (
 # None means "fall back to autodetected value".
 CUSTOM_KNOWN_GOOD_INPUT = {
   "AddProperty": [None, 10, None, None, None],
+  "AddPropertyForTemplate": [None, 10, None, None, None],
   "Apply": ["function() {}", None, None, None, None, None],
   "ArrayBufferSliceImpl": [None, None, 0, None],
   "ArrayConcat": ["[1, 'a']", None],