Backport operator precedence algorithm from here:
397b96f6d7
This eliminates unnecessary parentheses from our unparsed output and makes Spack's unparser
consistent with the one in upstream Python 3.9+, with one exception.
Our parser normalizes argument order when `py_ver_consistent` is set, so that star arguments
in function calls come last. We have to do this because Python 2's AST doesn't have information
about their actual order.
If we ever support only Python 3.9 and higher, we can easily switch over to `ast.unparse`, as
the unparsing is consistent except for this detail (modulo future changes to `ast.unparse`)
Add `astunparse` as `spack_astunparse`. This library unparses Python ASTs and we're
adding it under our own name so that we can make modifications to it.
Ultimately this will be used to make `package_hash` consistent across Python versions.
`sbang` now lives at https://github.com/spack/sbang, and it has its own
test suite that's more extensive than what's in Spack. We'll leave sbang
tests to sbang from now on, and just vendor `bin/sbang` directly.
Remaining `sbang` tests have to do with patching files, not with
`sbang`'s functionality.
This update also fixes a bug with `sbang` and multiple command line
arguments that was introduced in #19529. See:
* https://github.com/spack/sbang/pull/1
* https://github.com/spack/sbang/pull/2
- [x] include latest `sbang` from https://github.com/spack/sbang
- [x] remove old `sbang` tests from Spack
- [x] update `COPYRIGHT` and `cmd/license.py`