[clang-format] Add SpaceBeforeBrackets
Summary: Adds a new option SpaceBeforeBrackets to add spaces before brackets (i.e. int a[23]; -> int a [23];) This is present as an option in the Visual Studio C++ code formatting settings, but there was no matching setting in clang-format.
Reviewers: djasper, MyDeveloperDay, mitchell-stellar
Reviewed By: MyDeveloperDay
Subscribers: llvm-commits, cfe-commits, klimek
Patch by: Anteru
Tags: #clang, #clang-format, #llvm
Differential Revision: https://reviews.llvm.org/D6920