Do not use system ld in hc-kernel-assemble

[xw285cornell]

It seems hc-kernel-assemble is using the system ld, instead of $BINDIR/lld: https://github.com/RadeonOpenCompute/hcc/blob/44f47d857e1df2b1042a1d8f3a2e3225eee3d908/lib/hc-kernel-assemble.in#L185.

This will make it platform dependent (even if it works for the current ubuntu/centos, it doesn't work for some special systems). Can we change ld --> $BINDIR/lld?

[xw285cornell]

It seems to complain that lld is a generic tool, and asks me to use the specific ones:

stderr: lld is a generic driver.
Invoke ld.lld (Unix), ld64.lld (macOS), lld-link (Windows), wasm-ld (WebAssembly) instead

I can pass by changing it to $BINDIR/ld.lld, but wondering if there is anything better (if you care about windows, etc)