Add autoconf tests for size_t and ssize_t. Sort-of resolves public is…

…sue 79;

it would solve the problem if MSVC typically used autoconf. However, it gives
a natural place (config.h) to put the typedef even for MSVC.

R=jsbell


git-svn-id: https://snappy.googlecode.com/svn/trunk@80 03e5f5b5-db94-4691-08a0-1a8bf15f6143

configure.ac

@@ -18,6 +18,8 @@ AC_SUBST([LIBTOOL_DEPS])
 AC_PROG_CXX
 AC_LANG([C++])
 AC_C_BIGENDIAN
+AC_TYPE_SIZE_T
+AC_TYPE_SSIZE_T
 AC_CHECK_HEADERS([stdint.h stddef.h sys/mman.h sys/resource.h windows.h byteswap.h sys/byteswap.h sys/endian.h sys/time.h])
 
 # Don't use AC_FUNC_MMAP, as it checks for mappings of already-mapped memory,