build: add the ability to create a symlink for dsymutil

Add a `LLVM_INSTALL_CCTOOLS_SYMLINKS` to mirror
`LLVM_INSTALL_BINUTILS_SYMLINKS`.  For now, this allows us to create
symlinks for `dsymutil` to `llvm-dsymutil`.  This option is off by
default, but the user can enable it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326381 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed