Fix the setting of early exit on error for compile actions, to only happen when we are on a *nix shell. THis fixes building on mingw.

[SVN r20353]

tools/build

@@ -1 +1 @@
-Subproject commit b1539ce5de3dc2b35816f9994033ac542fc3c77b
+Subproject commit d92777a940933dd2e479b493a9089fc0489f1d81