Went with version >= 11.0 since it covers most of the major features
and should be pretty universally accessibly.
There are some issues:
1. indention of preprocessor directives:
Unfortunately there doesn't appear to be a switch for a seperate
'IndentWidth' for preprocessor directives vs. normal code so we
are stuck either not indenting the directives or over-indenting
them. i.e:
Desired:
```
#ifndef A
# define B
#endif
```
Options:
```
#ifndef A
# define B /* Two spaces instead of one. */
#endif
#ifndef C
#define D /* No spaces. */
#endif
```
Chose to over-indent as it generally seems easier to script
halving all pre-processor indentations than counting the nested
depth and indenting from scratch.
2. concatenation of lines missing semi-colons:
Throughout glibc there are macros used to setup aliasing that are
outside of functions and don't end in semi-colons i.e:
```
libc_hidden_def (__pthread_self)
weak_alias (__pthread_self, pthread_self)
```
clang-format reformats lines like these to:
```
libc_hidden_def (__pthread_self) weak_alias (__pthread_self, pthread_self)
```
which is generally undesirable.
Other than those two big concerns there are certainly some questions
diffs but for the most part it creates a easy to read and consistent
style.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
