code review 7712044: all: remove now-unnecessary unreachable panics

src/pkg/compress/flate/inflate.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // Package flate implements the DEFLATE compressed data format, described in
 // RFC 1951.  The gzip and zlib packages implement access to DEFLATE-based file
 // formats.
 package flate
 
 import (
@@ skipping 245 matching lines @@
                 if len(f.toRead) > 0 {
                         n := copy(b, f.toRead)
                         f.toRead = f.toRead[n:]
                         return n, nil
                 }
                 if f.err != nil {
                         return 0, f.err
                 }
                 f.step(f)
         }
-        panic("unreachable")
 }
 
 func (f *decompressor) Close() error {
         if f.err == io.EOF {
                 return nil
         }
         return f.err
 }
 
 // RFC 1951 section 3.2.7.
@@ skipping 211 matching lines @@
                 if !f.hfull && dist > f.hp {
                         f.err = CorruptInputError(f.roffset)
                         return
                 }
 
                 f.copyLen, f.copyDist = length, dist
                 if f.copyHist() {
                         return
                 }
         }
-        panic("unreached")
 }
 
 // copyHist copies f.copyLen bytes from f.hist (f.copyDist bytes ago) to itself.
 // It reports whether the f.hist buffer is full.
 func (f *decompressor) copyHist() bool {
         p := f.hp - f.copyDist
         if p < 0 {
                 p += len(f.hist)
         }
         for f.copyLen > 0 {
@@ skipping 178 matching lines @@
 func NewReaderDict(r io.Reader, dict []byte) io.ReadCloser {
         var f decompressor
         f.r = makeReader(r)
         f.hist = new([maxHist]byte)
         f.bits = new([maxLit + maxDist]int)
         f.codebits = new([numCodes]int)
         f.step = (*decompressor).nextBlock
         f.setDict(dict)
         return &f
 }