Update postmortem metadata generation script

This commit updates gen-postmortem-metadata.py to handle the
new ACCESSORS2 macro. Once that migration is complete,
ACCESSORS2 can be dropped from this script.

A constant is also added for SharedFunctionInfo's
kFunctionDataOffset, which was broken in
a55803a1.

See: https://github.com/nodejs/node-v8/issues/95
Change-Id: I5c3f960b4fd739a76f96d0ece9543574ff96be0f
Reviewed-on: https://chromium-review.googlesource.com/c/1392449Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58566}

tools/gen-postmortem-metadata.py

@@ -230,6 +230,9 @@ consts_misc = [
         'value': 'SimpleNumberDictionaryShape::kEntrySize' },
 
     { 'name': 'type_JSError__JS_ERROR_TYPE', 'value': 'JS_ERROR_TYPE' },
+
+    { 'name': 'class_SharedFunctionInfo__function_data__Object',
+        'value': 'SharedFunctionInfo::kFunctionDataOffset' },
 ];
 
 #
@@ -516,7 +519,8 @@ def parse_field(call):
 
         consts = [];
 
-        if (kind == 'ACCESSORS' or kind == 'ACCESSORS_GCSAFE'):
+        if (kind == 'ACCESSORS' or kind == 'ACCESSORS2' or
+            kind == 'ACCESSORS_GCSAFE'):
                 klass = args[0];
                 field = args[1];
                 dtype = args[2].replace('<', '_').replace('>', '_')
@@ -559,7 +563,7 @@ def load_fields_from_file(filename):
         # may span multiple lines and may contain nested parentheses.  We also
         # call parse_field() to pick apart the invocation.
         #
-        prefixes = [ 'ACCESSORS', 'ACCESSORS_GCSAFE',
+        prefixes = [ 'ACCESSORS', 'ACCESSORS2', 'ACCESSORS_GCSAFE',
                      'SMI_ACCESSORS', 'ACCESSORS_TO_SMI' ];
         current = '';
         opens = 0;