Not able to use gc-sections and LTO

[fwsGonzo]

It occured to me that the reason we cannot use certain features like -gc-sections on ld could be because the linker needs to be some clang-supported linker instead of GNU ld. Basically same reason why we can't use -flto.

[fwsGonzo]

LLVM has its own linker called lld which we should be using, found here: http://lld.llvm.org/

LLVM lld boasts faster speeds which could mean bigger memdisks might not be so annoying to link in: http://lld.llvm.org/NewLLD.html