[issue30070] Fix errors handling in the parser module

[Serhiy Storchaka]

New submission from Serhiy Storchaka:

Proposed patch fixes miscellaneous errors in errors handling in the parser module. This errors can cause leaking references, raising wrong exceptions, and even crashing.

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components: Extension Modules
messages: 291645
nosy: benjamin.peterson, serhiy.storchaka
priority: normal
severity: normal
stage: patch review
status: open
title: Fix errors handling in the parser module
type: crash
versions: Python 2.7, Python 3.5, Python 3.6, Python 3.7

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue30070>
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