Simplify expressions involving boolean constants with clang-tidy

Patch by Richard (legalize at xmission dot com).

Differential Revision: http://reviews.llvm.org/D8154

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231617 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/PeepholeOptimizer.cpp

@@ -915,7 +915,7 @@ bool PeepholeOptimizer::optimizeCoalescableCopy(MachineInstr *MI) {
   // => v0 = COPY v1
   // Currently we haven't seen motivating example for that and we
   // want to avoid untested code.
-  NumRewrittenCopies += Changed == true;
+  NumRewrittenCopies += Changed;
   return Changed;
 }