[clang-tidy] New checker to replace dynamic exception specifications

Summary:
New checker to replace dynamic exception
specifications

This is an alternative to D18575 which relied on reparsing the decl to
find the location of dynamic exception specifications, but couldn't
deal with preprocessor conditionals correctly without reparsing the
entire file.

This approach uses D20428 to find dynamic exception specification
locations and handles all cases correctly.

Reviewers: aaron.ballman, alexfh

Reviewed By: aaron.ballman, alexfh

Subscribers: xazax.hun, mgehre, malcolm.parsons, mgorny, JDevlieghere, cfe-commits, Eugene.Zelenko, etienneb

Patch by Don Hinton!

Differential Revision: https://reviews.llvm.org/D20693

llvm-svn: 304977