This caused gcc to receive the actual argument "''" or for example
"'-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'" and then error
with
gcc: error: '-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now': No such file or directory

Furthermore, the trimpath arguments tried to trim an actual path
resembling "'$PWD'", which did nothing as the literal single quotes were
not valid in this context.

Both issues can be fixed by assigning arguments to the go compiler using
the argv notation { "-flag", "argument" } rather than { "-flag=argument" }.