[clang-tidy] modernize-use-equals-default avoid adding redundant semicolons

Summary:
`modernize-use-equals-default` replaces default constructors/destructors with `= default;`. When the optional semicolon after a member function is present, this results in two consecutive semicolons.

This patch checks to see if the next non-comment token after the code to be replaced is a semicolon, and if so offers a replacement of `= default` rather than `= default;`.

This patch adds trailing comments and semicolons to about 5 existing tests.

Reviewers: malcolm.parsons, angelgarcia, aaron.ballman, alexfh

Patch by: poelmanc

Subscribers: MyDeveloperDay, JonasToth, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70144