[NFC] fix trivial typos in document and comments

"not not" -> "not" etc

llvm-svn: 330083
diff --git a/llvm/lib/Transforms/Scalar/MergeICmps.cpp b/llvm/lib/Transforms/Scalar/MergeICmps.cpp
index 5635f54..bb1b8a5 100644
--- a/llvm/lib/Transforms/Scalar/MergeICmps.cpp
+++ b/llvm/lib/Transforms/Scalar/MergeICmps.cpp
@@ -231,7 +231,7 @@
   DenseSet<Instruction *> BlockInsts(
       {Lhs_.GEP, Rhs_.GEP, Lhs_.LoadI, Rhs_.LoadI, CmpI, BranchI});
   // TODO(courbet): Can we allow some other things ? This is very conservative.
-  // We might be able to get away with anything does does not have any side
+  // We might be able to get away with anything does not have any side
   // effects outside of the basic block.
   // Note: The GEPs and/or loads are not necessarily in the same block.
   for (const Instruction &Inst : *BB) {