Remove _sre.c from the build.

On testing this, I discovered that the 'pickle' module pulls in 'struct'
and 'binascii', which is a few thousand lines of C code.

build/compile.sh

@@ -95,7 +95,6 @@ MODOBJS='
Modules/posixmodule.c
Modules/errnomodule.c
Modules/pwdmodule.c
Modules/_sre.c
Modules/_codecsmodule.c
Modules/_weakref.c
Modules/zipimport.c

build/static-c-modules.txt

@@ -9,8 +9,8 @@ posix posixmodule.c		# posix (UNIX) system calls
errno errnomodule.c		# posix (UNIX) errno values
pwd pwdmodule.c			# this is needed to find out the user's home dir
				# if $HOME is not set
_sre _sre.c			# Fredrik Lundh's new regular expressions
_codecs _codecsmodule.c		# access to the builtin codecs and codec registry

_weakref _weakref.c             # weak references

# The zipimport module is always imported at startup. Having it as a