Define clang lld flags for hosts.

* Add -fuse-ld=lld to hostGlobalLldflags.
* Set up *ClangLldflags variables for hosts.
  They are the same as *ClangLdflags, but could be changed in the future.

Bug: 73768157
Test: make checkbuild
Change-Id: I3d61504ab7262d472bbf933df7c1a9bef62519e1