Bug#487310: GCC ignores -Wno-strict-aliasing

[Ian Jackson <ian@davenant.greenend.org.uk>]

I have cloned this bug so that I can reassign this clone to GCC
See the transcript in the original report.  We see this:

  cc -g -Wall -Wmissing-prototypes -Wstrict-prototypes -Werror -O2 -Wno-pointer-sign -Wno-strict-aliasing -fPIC  -I/usr/include/tcl8.4 -I../base -DTCL_MEM_DEBUG -MMD -o 
  hook.o -c hook.c
  cc1: warnings being treated as errors
  hook.c: In function 'hbytes_t_sfa':
  hook.c:108: error: dereferencing type-punned pointer will break strict-aliasing rules

Ian.