* libc/include/stdio.h: Add new reentrant I/O prototypes for
read/write functions. Change getc/putc macros to have reentrant underlying
macros/functions. This includes __sgetc_raw_r, __sgetc_r, and __sputc_r.
* libc/stdio/fgetc.c: Fix and/or add reentrant version to call
new reentrant I/O functions/macros for reading/writing.
* libc/stdio/fgets.c: Ditto.
* libc/stdio/fputc.c: Ditto.
* libc/stdio/fputs.c: Ditto.
* libc/stdio/fread.c: Ditto.
* libc/stdio/fseek.c: Ditto.
* libc/stdio64/fseeko64.c: Ditto.
* libc/stdio/fwrite.c: Ditto.
* libc/stdio/getc.c: Ditto.
* libc/stdio/getc_u.c: Ditto.
* libc/stdio/getchar.c: Ditto.
* libc/stdio/getchar_u.c: Ditto.
* libc/stdio/putc.c: Ditto.
* libc/stdio/putc_u.c: Ditto.
* libc/stdio/putchar.c: Ditto.
* libc/stdio/puts.c: Ditto.
* libc/stdio/vfprintf.c: Ditto.
* libc/stdio/vfscanf.c: Ditto.
* libc/stdio/fvwrite.c: Change __sfvwrite into reentrant __sfvwrite_r.
Change all previous callers of __sfvwrite. Set errno to EBADF and
set error flag on if attempt is made to write to file that does not
allow writing.
* libc/stdio/fvwrite.h: Fix new reentrant prototypes.
* libc/stdio/local.h: Ditto.
* libc/stdio/refill.c: Turn __srefill into reentrant __srefill_r.
Set errno to EBADF and the error flag on if attempt is made to
read unreadable file. Change all previous callers of __srefill.
* libc/stdio/rget.c
* libc/stdio/wbuf.c: Turn __swbuf into reentrant __swbuf_r. Change
all previous callers of __swbuf.
* libc/sys/linux/machine/i386/huge_val.h: Ifdef out file contents since
huge value macros are already defined correctly for i386 by <math.h>.
* libc/stdio/fread.c (fread): For non-space-optimized case,
add special code for unbuffered files to use user buffer and
only require one low-level system read.
* libc/include/stdio.h (FILE): define __SCLE for "convert line
endings" for Cygwin.
(__sgetc): convert line endings if needed
(__sputc): ditto
* libc/stdio/fdopen.c (_fdopen_r): Remember if we opened in text mode
* libc/stdio/fopen.c (_fopen_r): ditto
* libc/stdio/freopen.c (freopen): ditto
* libc/stdio/fread.c (fread): perform CRLF conversions if __SCLE
* libc/stdio/fvwrite.c (__sfvwrite): ditto