supplementary Go tools

 This subrepository holds the source for various packages and tools that
 support the Go programming language.
 .
 Some of the tools, godoc and vet for example, used to be included in the
 golang-go package. Others, including the Go oracle and the test coverage tool,
 can be fetched with "go get".
 .
 Packages include a type-checker for Go and an implementation of the Static
 Single Assignment form (SSA) representation for Go programs.