the bash scripts and makefiles for building go didn't take into account
the fact $GOROOT / $GOBIN could both be directories containing whitespaces,
and was not possible to build it in such a situation.
this commit adjusts the various makefiles/scripts to make it aware of that
possibility, and now it builds successfully when using a path with whitespaces
as well.
Fixes#115.
R=rsc, dsymonds1
https://golang.org/cl/157067
deciding what the host process support is.
this makes a cross-compiling (e.g., GOOS=nacl) build
still generate valid host debugger binaries.
R=r
DELTA=5 (0 added, 0 deleted, 5 changed)
OCL=34878
CL=34889
