Summary:
The issue is that for array subscript like:
```
arr[[Foo() bar]];
```
ClangFormat will recognize it as C++11 attribute syntax and put a space between 'arr' and first '[', like:
```
arr [[Foo() bar]];
```
Now it is fixed. Tested with:
```
ninja FormatTests
```
Reviewers: benhamilton
Reviewed By: benhamilton
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D54288
llvm-svn: 346566