HexagonDesc: Update LLVMBuild.txt.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219071 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] HexagonTests: Update LINK_COMPONENTS.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219072 91177308-0d34-0410-b5e6-96231b3b80d8
HexagonMCCodeEmitter.cpp: Prune 2nd redundant \brief. [-Wdocumentation]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219073 91177308-0d34-0410-b5e6-96231b3b80d8