Revert r248047 and fix the problem properly

In r248047, I attempted to fix a build breakage introduced by using
llvm's regex support from lldb-mi. However, my approach was flawed
when LLVM and lldb are dynamically linked, in which case two copies
of LLVMSupport would end up in memory, causing crashes on lldb start up.
Instead, use LINK_COMPONENTS to make sure lldb-mi has access to the
LLVMSupport symbols without causing duplication in the dynamic library
case.

llvm-svn: 250751