cmd/gofmt: remove -tabwidth and -tabs flags (CL 52170043)
liblink: pull linker i/o into separate liblink C library (CL 35790044)
misc/dist: renamed misc/makerelease (CL 39920043)
runtime: output how long goroutines are blocked (CL 50420043)
syscall: add NewCallbackCDecl to use for windows callbacks (CL 36180044)
testing: diagnose buggy tests that panic(nil) (CL 55780043)