Second, the timer channel associated with a `Timer` or `Ticker` is
now unbuffered, with capacity 0.
The main effect of this change is that Go now guarantees
that for any call to a `Reset` or `Stop` method, no stale values
prepared before that call will be sent or received after the call.
Earlier versions of Go used channels with a one-element buffer,
making it difficult to use `Reset` and `Stop` correctly.

	EXTRACTPS $4, X2, (BX)          // ERROR "invalid instruction"
	EXTRACTPS $-1, X2, (BX)         // ERROR "invalid instruction"
	// VSIB addressing does not permit non-vector (X/Y)
	// scaled index register.
	VPGATHERDQ X12,(R13)(AX*2), X11 // ERROR "invalid instruction"
	VPGATHERDQ X2, 664(BX*1), X1    // ERROR "invalid instruction"
	VPGATHERDQ Y2, (BP)(AX*2), Y1   // ERROR "invalid instruction"