Summary:
Detects when the integral literal or floating point (decimal or hexadecimal)
literal has non-uppercase suffix, and suggests to make the suffix uppercase,
with fix-it.
All valid combinations of suffixes are supported.
```
auto x = 1; // OK, no suffix.
auto x = 1u; // warning: integer literal suffix 'u' is not upper-case
auto x = 1U; // OK, suffix is uppercase.
...
```
References:
* [[ https://wiki.sei.cmu.edu/confluence/pages/viewpage.action?pageId=87152241 | CERT DCL16-C ]]
* MISRA C:2012, 7.3 - The lowercase character "l" shall not be used in a literal suffix
* MISRA C++:2008, 2-13-4 - Literal suffixes shall be upper case
Reviewers: JonasToth, aaron.ballman, alexfh, hokein, xazax.hun
Reviewed By: aaron.ballman
Subscribers: Eugene.Zelenko, mgorny, rnkovacs, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D52670
llvm-svn: 344755