internal/pkgbits: s/errorf/panicf/ because that's what it is

Make it obvious that this function panics.

Change-Id: I272142d2cf7132aa8915f8f4b5945834376db062
Reviewed-on: https://go-review.googlesource.com/c/go/+/606935


Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/internal/pkgbits/decoder.go

@@ -84,7 +84,7 @@ func NewPkgDecoder(pkgPath, input string) PkgDecoder {
 
 	switch pr.version {
 	default:
-		panic(fmt.Errorf("unsupported version: %v", pr.version))
+		panicf("unsupported version: %v", pr.version)
 	case 0:
 		// no flags
 	case 1:
@@ -136,7 +136,7 @@ func (pr *PkgDecoder) AbsIdx(k RelocKind, idx Index) int {
 		absIdx += int(pr.elemEndsEnds[k-1])
 	}
 	if absIdx >= int(pr.elemEndsEnds[k]) {
-		errorf("%v:%v is out of bounds; %v", k, idx, pr.elemEndsEnds)
+		panicf("%v:%v is out of bounds; %v", k, idx, pr.elemEndsEnds)
 	}
 	return absIdx
 }
@@ -242,7 +242,7 @@ type Decoder struct {
 
 func (r *Decoder) checkErr(err error) {
 	if err != nil {
-		errorf("unexpected decoding error: %w", err)
+		panicf("unexpected decoding error: %w", err)
 	}
 }
 

src/internal/pkgbits/encoder.go

@@ -194,7 +194,7 @@ func (w *Encoder) Flush() Index {
 
 func (w *Encoder) checkErr(err error) {
 	if err != nil {
-		errorf("unexpected encoding error: %v", err)
+		panicf("unexpected encoding error: %v", err)
 	}
 }
 
@@ -359,7 +359,7 @@ func (w *Encoder) Value(val constant.Value) {
 func (w *Encoder) scalar(val constant.Value) {
 	switch v := constant.Val(val).(type) {
 	default:
-		errorf("unhandled %v (%v)", val, val.Kind())
+		panicf("unhandled %v (%v)", val, val.Kind())
 	case bool:
 		w.Code(ValBool)
 		w.Bool(v)

src/internal/pkgbits/support.go

@@ -12,6 +12,6 @@ func assert(b bool) {
 	}
 }
 
-func errorf(format string, args ...any) {
+func panicf(format string, args ...any) {
 	panic(fmt.Errorf(format, args...))
 }