Proposed in it "LD ?= gcc" assignment doesn't works both with existing
makefiles and with current version of the makefile template. User must
define LD in it's makefile to let them work. That is bad.
This workaround uses $origin function to check for redefinition of LD
variable in user's makefile.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40739 a95241bf-73f2-0310-859d-f6bbb57e9c96