link: take absolute path of main file (#1727)
link: take absolute path of main file (#1727)

Windows has trouble with long paths. Other paths to .a files are
absolutized already.

Related bazelbuild/bazel-gazelle#321
Xjs/rules_go,Xjs/rules_go,bazelbuild/rules_go,bazelbuild/rules_go,Xjs/rules_go,bazelbuild/rules_go,Xjs/rules_go,Xjs/rules_go,bazelbuild/rules_go,bazelbuild/rules_go