Recommit r183298+r183300 'Get rid of VTableContext::ComputeMethodVTableIndices() and VTableContext::getNumVirtualFunctionPointers()'

In r183298, I've used llvm::SmallPtrSet<..., 8> instead of llvm::SmallVector<..., 8> for NewVirtualFunctionsTy by mistake.
This only manifested when a class had more than 8 virtual functions, which wasn't covered by unit-tests

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183310 91177308-0d34-0410-b5e6-96231b3b80d8
UTF-8 support for clang-format.

Summary:
Detect if the file is valid UTF-8, and if this is the case, count code
points instead of just using number of bytes in all (hopefully) places, where
number of columns is needed. In particular, use the new
FormatToken.CodePointCount instead of TokenLength where appropriate.
Changed BreakableToken implementations to respect utf-8 character boundaries
when in utf-8 mode.

Reviewers: klimek, djasper

Reviewed By: djasper

CC: cfe-commits, rsmith, gribozavr

Differential Revision: http://llvm-reviews.chandlerc.com/D918

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183312 91177308-0d34-0410-b5e6-96231b3b80d8