MSR	R16, DBGWVR14_EL1                  // d00e10d5
	MSR	R5, DBGWVR15_EL1                   // c50f10d5
	MRS	DCZID_EL0, R21                     // f5003bd5
	MRS	DISR_EL1, R8                       // 28c138d5
	MSR	R5, DISR_EL1                       // 25c118d5
	MRS	DIT, R29                           // bd423bd5
	MSR	R22, DIT                           // b6421bd5
	MRS	DLR_EL0, R25                       // 39453bd5

// It uses $CC if set, or else $GCC, or else the compiler recorded
// during the initial build as defaultCC.
// defaultCC is defined in zdefaultcc.go, written by cmd/dist.
//
// The compiler command line is split into arguments on whitespace. Quotes
// are understood, so arguments may contain whitespace.
//
// checkGCCBaseCmd confirms that the compiler exists in PATH, returning