Fix a few typos in comments

Apply the following spelling fixes:
$ git grep -F -l 'relevent' |
  xargs sed -i 's/relevent/relevant/g'
$ git grep -F -l 'checked fot' |
  xargs sed -i 's/checked fot/checked for/g'
$ git grep -F -l "could't" |
  xargs sed -i "s/could't/couldn't/g"
$ git grep -F -l 'wheter' | grep -Fv ChangeLog.old |
  xargs sed -i 's/wheter/whether/g'
$ git grep -F -l 'neccessary' | grep -Fv ChangeLog.old |
  xargs sed -i 's/neccessary/necessary/g'
$ git grep -F -l 'ouput' |
  xargs sed -i 's/ouput/output/g'
$ git grep -F -w -l 'iput' |
  xargs sed -i 's/iput/input/g'

This is inspired by a gnulib bug report at
https://lists.gnu.org/archive/html/bug-gnulib/2019-01/msg00081.html

* argp/argp-help.c: Fix typo in comment.
* misc/sys/cdefs.h: Likewise.
* posix/regexec.c (sift_states_iter_mb): Likewise.
* socket/sockatmark.c: Likewise.
* socket/sys/socket.h: Likewise.
* sysdeps/ia64/fpu/libm_sincos_large.S: Likewise.
* sysdeps/ia64/fpu/libm_sincosl.S: Likewise.
* sysdeps/ia64/fpu/s_cosl.S: Likewise.
* sysdeps/ieee754/dbl-64/k_rem_pio2.c: Likewise.
* sysdeps/unix/sockatmark.c: Likewise.
* time/strptime_l.c: Likewise.

ChangeLog

@@ -1,3 +1,17 @@
+2019-01-12  Dmitry V. Levin  <ldv@altlinux.org>
+
+	* argp/argp-help.c: Fix typo in comment.
+	* misc/sys/cdefs.h: Likewise.
+	* posix/regexec.c (sift_states_iter_mb): Likewise.
+	* socket/sockatmark.c: Likewise.
+	* socket/sys/socket.h: Likewise.
+	* sysdeps/ia64/fpu/libm_sincos_large.S: Likewise.
+	* sysdeps/ia64/fpu/libm_sincosl.S: Likewise.
+	* sysdeps/ia64/fpu/s_cosl.S: Likewise.
+	* sysdeps/ieee754/dbl-64/k_rem_pio2.c: Likewise.
+	* sysdeps/unix/sockatmark.c: Likewise.
+	* time/strptime_l.c: Likewise.
+
 2019-01-11  TAMUKI Shoichi  <tamuki@linet.gr.jp>
 
 	* time/strftime_l.c (__strftime_internal): Use "L_" macros, also add a

argp/argp-help.c

@@ -1540,7 +1540,7 @@ argp_doc (const struct argp *argp, const struct argp_state *state,
 }
 
 /* Output a usage message for ARGP to STREAM.  If called from
-   argp_state_help, STATE is the relevent parsing state.  FLAGS are from the
+   argp_state_help, STATE is the relevant parsing state.  FLAGS are from the
    set ARGP_HELP_*.  NAME is what to use wherever a `program name' is
    needed. */
 static void

misc/sys/cdefs.h

@@ -337,7 +337,7 @@
    semantics.
 
    clang++ identifies itself as gcc-4.2, but has support for GNU inlining
-   semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
+   semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
    __GNUC_GNU_INLINE__ macro definitions.  */
 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
      || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \

posix/regexec.c

@@ -2207,7 +2207,7 @@ sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx,
 			    dfa->nexts[node_idx]))
     /* The node can't accept the "multi byte", or the
        destination was already thrown away, then the node
-       could't accept the current input "multi byte".   */
+       couldn't accept the current input "multi byte".   */
     naccepted = 0;
   /* Otherwise, it is sure that the node could accept
      'naccepted' bytes input.  */

socket/sockatmark.c

@@ -18,7 +18,7 @@
 #include <errno.h>
 #include <sys/socket.h>
 
-/* Determine wheter socket is at a out-of-band mark.  */
+/* Determine whether socket is at a out-of-band mark.  */
 int
 sockatmark (int fd)
 {

socket/sys/socket.h

@@ -251,7 +251,7 @@ extern int shutdown (int __fd, int __how) __THROW;
 
 
 #ifdef __USE_XOPEN2K
-/* Determine wheter socket is at a out-of-band mark.  */
+/* Determine whether socket is at a out-of-band mark.  */
 extern int sockatmark (int __fd) __THROW;
 #endif
 

sysdeps/ia64/fpu/libm_sincos_large.S

@@ -223,7 +223,7 @@
 //           = (-1)^i_0 * [cos(r) - c*r] if i_1 = 1
 //
 //  because |r| is small and thus the second terms in the correction
-//  are unneccessary.
+//  are unnecessary.
 //
 //  Finally, sin(r) and cos(r) are approximated by polynomials of
 //  moderate lengths.

sysdeps/ia64/fpu/libm_sincosl.S

@@ -205,7 +205,7 @@
 //           = (-1)^i_0 * [cosl(r) - c*r] if i_1 = 1
 //
 //  because |r| is small and thus the second terms in the correction
-//  are unneccessary.
+//  are unnecessary.
 //
 //  Finally, sinl(r) and cosl(r) are approximated by polynomials of
 //  moderate lengths.

sysdeps/ia64/fpu/s_cosl.S

@@ -212,7 +212,7 @@
 //           = (-1)^i_0 * [cosl(r) - c*r] if i_1 = 1
 //
 //  because |r| is small and thus the second terms in the correction
-//  are unneccessary.
+//  are unnecessary.
 //
 //  Finally, sinl(r) and cosl(r) are approximated by polynomials of
 //  moderate lengths.

sysdeps/ieee754/dbl-64/k_rem_pio2.c

@@ -45,7 +45,7 @@ static char rcsid[] = "$NetBSD: k_rem_pio2.c,v 1.7 1995/05/10 20:46:25 jtc Exp $
  *			z    = (z-x[i])*2**24
  *
  *
- *	y[]	ouput result in an array of double precision numbers.
+ *	y[]	output result in an array of double precision numbers.
  *		The dimension of y[] is:
  *			24-bit  precision	1
  *			53-bit  precision	2

sysdeps/unix/sockatmark.c

@@ -18,7 +18,7 @@
 #include <sys/ioctl.h>
 #include <sys/socket.h>
 
-/* Determine wheter socket is at a out-of-band mark.  */
+/* Determine whether socket is at a out-of-band mark.  */
 int
 sockatmark (int fd)
 {

time/strptime_l.c

@@ -306,7 +306,7 @@ __strptime_internal (const char *rp, const char *fmt, struct tm *tmp,
 	}
 
       /* Any character but `%' must be matched by the same character
-	 in the iput string.  */
+	 in the input string.  */
       if (*fmt != '%')
 	{
 	  match_char (*fmt++, *rp++);