Remove global linker search paths

Remove the global linker search path, as it can cause spurious build
failures.  If a library with the same name as a system library is in the
process of being written to the directory in the global search path, and
the linker may try to read the partially-written built one instead of the
system one.  We already use full paths to libraries for target builds,
do the same for host builds.  Also remove the normalize library
functions, they are no longer necessary.

Test: m -j checkbuild
Bug: 31393456
Change-Id: If9fc631e111f568c700fd73e103445c30d7e9d11