Remove redundant 'llvm::' qualifications


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172358 91177308-0d34-0410-b5e6-96231b3b80d8
Fix broken link to LangRef


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172359 91177308-0d34-0410-b5e6-96231b3b80d8
Documentation: use monospaced font for intrinsics' names


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172360 91177308-0d34-0410-b5e6-96231b3b80d8