Fixed column shift when formatting line containing bit shift operators

Summary:
During clang-format source lexing >> and << operators are split and
treated as two less/greater operators but column position of following
tokens was not adjusted accordingly.

Fixes PR26887

Patch by Paweł Żukowski.

Reviewers: djasper

Subscribers: malcolm.parsons, mprobst, klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D25439

llvm-svn: 285934