clang-format: Add support for formatting (some) lambdas with explicit template parameters.

This patch makes cases work where the lambda's template list doesn't
contain any of + - ! ~ / % << | || && ^ == != >= <= ? : true false
(see added FIXME).

Ports r359967 to clang-format.

Differential Revision: https://reviews.llvm.org/D67246

llvm-svn: 371854