C++ compilability -- don't jump across variable initialization

C++ is picker than C about when you can "goto" across a variable being
defined.  The fix is to just minimize the variable's scope inside an
extra set of brackets.

Without this change, g++ has the following errors:

  transcode.c:590: error: jump to label 'resume_label3'
  transcode.c:514: error:   from here
  transcode.c:582: error:   crosses initialization of 'const unsigned char* p'
  transcode.c:2124: error: jump to label 'set_encs'
  transcode.c:2184: error:   from here
  transcode.c:2088: error:   skips initialization of 'const char* err'
  transcode.c:2089: error:   skips initialization of 'size_t error_len'
  transcode.c:2090: error:   skips initialization of 'mrb_value bytes'
  transcode.c:2091: error:   skips initialization of 'mrb_value dumped'
  transcode.c:2092: error:   skips initialization of 'size_t readagain_len'
  transcode.c:2093: error:   skips initialization of 'mrb_value bytes2'

0 files changed, 0 insertions, 0 deletions