[PatternMatch] Use generic One,Two,ThreeOps_match classes (NFC).

Currently we have a few duplicated matcher classes, which all do pretty
much the same thing. This patch introduces generic
One,Tow,ThreeOps_match classes which take the opcode the match as
template argument.

Reviewers: SjoerdMeijer, dneilson, spatel, arsenm

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D51044

llvm-svn: 342058