Also adjust some of dsymutil's headers to put the header guards at the top,
otherwise the compiler will not recognize them as header guards.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341323 91177308-0d34-0410-b5e6-96231b3b80d8
Combine expression patterns to form expressions with fewer, simple instructions.
This pass does not modify the CFG.
For example, this pass reduce width of expressions post-dominated by TruncInst
into smaller width when applicable.
It differs from instcombine pass in that it contains pattern optimization that
requires higher complexity than the O(1), thus, it should run fewer times than
instcombine pass.
Differential Revision: https://reviews.llvm.org/D38313
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323321 91177308-0d34-0410-b5e6-96231b3b80d8
