Update pycparser to 2.20

[pyup-bot]

This PR updates pycparser from 2.14 to 2.20.

Changelog

2.20

- 61: Fix slow backtracking when parsing strings.
- 99: Parser for FuncDecl incorrectly sets declname attribute on return type.
- 310: Fix crash when file starts with a semicolon.
- 313: Fix array type generation.
- 314: Fix failed parsing of unnamed function parameters with array dim
 qualifiers.
- 315: Fix pointer type generation.
- 324: Fixes for u/l constant integer suffix.
- 346: Fix error transforming an empty switch.
- 350: Recognize integer multicharacter constants like 'ABCD'.
- 363: Fix incorrect AST when parsing offsetof.

2.19

- PR 277: Fix parsing of floating point literals
- PR 254: Add support for parsing empty structs
- PR 240: Fix enum formatting in generated C code (also 216)
- PR 222: Add support for pragma in struct declarations
- There are reports that this release doesn't work with Python 2.6 (281).
 Please note that the minimal supported version is 2.7; the required versions
 are listed in the README file.

2.18

- PR 161 & 184: Update bundled PLY version to 3.10
- PR 158: Add support for the __int128 type.
- PR 169: Handle more tricky TYPEID in declarators.
- PR 178: Add columns to the coord of each node

2.17

- Again functionality identical to 2.15 and 2.16; the difference is that the
 tarball now contains Python files with properly set permissions.

2.16

- Functionally identical to 2.15, but fixes a packaging problem that caused
 failed installation (_build_tables wasn't rerun in the pycparser/ dir).

2.15

- PR 121: Update bundled PLY version to 3.8
- Issue 117: Fix parsing of extra semi-colons inside structure declarations.
- PR 109: Update c_generator to add {} around nested named initializers.
- PR 101: Added support for parsing pragmas into the AST.
- Additional fake headers and typedefs, manifest fixes (97, 106, 111).
- Testing with Python 3.5 instead of 3.3 now (3.4 and 3.5 are the 3.x versions
 tested).
- PR 145: More complete support for offsetof()
- Issue 116: Fix line numbers recorded for empty and compound statements.
- Minor performance improvement to the invalid string literal regex.

Links

• PyPI: https://pypi.org/project/pycparser
• Changelog: https://pyup.io/changelogs/pycparser/
• Repo: https://github.com/eliben/pycparser

[pyup-bot]

Closing this in favor of #765