reduce spurious inclusion of libc.h

libc.h was intended to be a header for access to global libc state and
related interfaces, but ended up included all over the place because
it was the way to get the weak_alias macro. most of the inclusions
removed here are places where weak_alias was needed. a few were
recently introduced for hidden. some go all the way back to when
libc.h defined CANCELPT_BEGIN and _END, and all (wrongly implemented)
cancellation points had to include it.

remaining spurious users are mostly callers of the LOCK/UNLOCK macros
and files that use the LFS64 macro to define the awful *64 aliases.

in a few places, new inclusion of libc.h is added because several
internal headers no longer implicitly include libc.h.

declarations for __lockfile and __unlockfile are moved from libc.h to
stdio_impl.h so that the latter does not need libc.h. putting them in
libc.h made no sense at all, since the macros in stdio_impl.h are
needed to use them correctly anyway.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/stdio/ftell.c b/src/stdio/ftell.c
index bb62897a..aad352bd 100644
--- a/src/stdio/ftell.c
+++ b/src/stdio/ftell.c
@@ -1,6 +1,7 @@
 #include "stdio_impl.h"
 #include <limits.h>
 #include <errno.h>
+#include "libc.h"
 
 off_t __ftello_unlocked(FILE *f)
 {