CCVER=gcc46: Separate LDFLAGS meant for gcc and ld

CCVER=gcc46: Separate LDFLAGS meant for gcc and ld

The same LDFLAGS variable was being applied to gcc and ld.  Apparently
gcc 4.4 and below recognized and accepted the -m switch and passed it
on to the linker, but gcc 4.6 wasn't handling it.

A new variable COMPILER_LDFLAGS has been created alongside LDFLAGS.  The
former is meant to be passed to gcc and the latter is passed to ld.