maint: avoid syntax-check failures from recent commit

* gl/lib/dtimespec-bound.h: Indent, Spellcheck.
* gl/local.mk: Add new gl files.

gl/lib/dtimespec-bound.h

@@ -18,21 +18,21 @@
 /* written by Paul Eggert */
 
 #ifndef DTIMESPEC_BOUND_H
-#define DTIMESPEC_BOUND_H 1
+# define DTIMESPEC_BOUND_H 1
 
 /* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
-#if !_GL_CONFIG_H_INCLUDED
- #error "Please include config.h first."
-#endif
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
 
-#include <errno.h>
-#include <float.h>
-#include <math.h>
+# include <errno.h>
+# include <float.h>
+# include <math.h>
 
 _GL_INLINE_HEADER_BEGIN
-#ifndef DTIMESPEC_BOUND_INLINE
-# define DTIMESPEC_BOUND_INLINE _GL_INLINE
-#endif
+# ifndef DTIMESPEC_BOUND_INLINE
+#  define DTIMESPEC_BOUND_INLINE _GL_INLINE
+# endif
 
 /* If C is positive and finite, return the least floating point value
    greater than C.  However, if 0 < C < (2 * DBL_TRUE_MIN) / (DBL_EPSILON**2),
@@ -63,7 +63,7 @@ dtimespec_bound (double c, int err)
   /* This is the first part of Algorithm 2 of:
      Rump SM, Zimmermann P, Boldo S, Melquiond G.
      Computing predecessor and successor in rounding to nearest.
-     BIT Numer Math. 2009;49(419-431).
+     BIT Numerical Mathematics. 2009;49(419-431).
      <https://doi.org/10.1007/s10543-009-0218-z>
      The rest of Algorithm 2 is not needed because numbers less than
      the predecessor of 1e-9 merely need to stay less than 1e-9.  */

gl/local.mk

@@ -22,6 +22,8 @@ gl/lib/buffer-lcm.h \
 gl/lib/cl-strtod.c \
 gl/lib/cl-strtod.h \
 gl/lib/cl-strtold.c \
+gl/lib/dtimespec-bound.c \
+gl/lib/dtimespec-bound.h \
 gl/lib/fadvise.c \
 gl/lib/fadvise.h \
 gl/lib/fd-reopen.c \
@@ -57,6 +59,7 @@ gl/local.mk \
 gl/modules/buffer-lcm \
 gl/modules/cl-strtod \
 gl/modules/cl-strtold \
+gl/modules/dtimespec-bound \
 gl/modules/fadvise \
 gl/modules/fadvise-tests \
 gl/modules/fd-reopen \