Tests to ensure the basic features of go_binary are working as expected.
Hello is a basic "hello world" program that doesn't do anything interesting. Useful as a primitive smoke test -- if this doesn't build, nothing will.
Test that a go_binary rule can write its executable file with a custom name in the package directory (not the mode directory).
Test that a go_binary with many imports with long names can be linked. This makes sure we don't exceed command-line length limits with -I and -L flags. Verifies #1637.