Update from Gnulib

This incorporates:
2020-02-21 largefile: remove _DARWIN_USE_64_BIT_INODE
2020-02-21 Add ‘extern "C"’ to count-one-bits.h etc.
* lib/count-leading-zeros.h, lib/count-one-bits.h:
* lib/count-trailing-zeros.h, m4/largefile.m4: Copy from Gnulib.

lib/count-leading-zeros.h

@@ -30,6 +30,10 @@ _GL_INLINE_HEADER_BEGIN
 # define COUNT_LEADING_ZEROS_INLINE _GL_INLINE
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Assuming the GCC builtin is BUILTIN and the MSC builtin is MSC_BUILTIN,
    expand to code that computes the number of leading zeros of the local
    variable 'x' of type TYPE (an unsigned integer type) and return it
@@ -108,6 +112,10 @@ count_leading_zeros_ll (unsigned long long int x)
                        unsigned long long int);
 }
 
+#ifdef __cplusplus
+}
+#endif
+
 _GL_INLINE_HEADER_END
 
 #endif /* COUNT_LEADING_ZEROS_H */

lib/count-one-bits.h

@@ -30,6 +30,10 @@ _GL_INLINE_HEADER_BEGIN
 # define COUNT_ONE_BITS_INLINE _GL_INLINE
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Expand to code that computes the number of 1-bits of the local
    variable 'x' of type TYPE (an unsigned integer type) and return it
    from the current function.  */
@@ -129,6 +133,10 @@ count_one_bits_ll (unsigned long long int x)
   COUNT_ONE_BITS (__builtin_popcountll, __popcnt64, unsigned long long int);
 }
 
+#ifdef __cplusplus
+}
+#endif
+
 _GL_INLINE_HEADER_END
 
 #endif /* COUNT_ONE_BITS_H */

lib/count-trailing-zeros.h

@@ -30,6 +30,10 @@ _GL_INLINE_HEADER_BEGIN
 # define COUNT_TRAILING_ZEROS_INLINE _GL_INLINE
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Assuming the GCC builtin is BUILTIN and the MSC builtin is MSC_BUILTIN,
    expand to code that computes the number of trailing zeros of the local
    variable 'x' of type TYPE (an unsigned integer type) and return it
@@ -100,6 +104,10 @@ count_trailing_zeros_ll (unsigned long long int x)
                         unsigned long long int);
 }
 
+#ifdef __cplusplus
+}
+#endif
+
 _GL_INLINE_HEADER_END
 
 #endif

m4/largefile.m4

@@ -113,9 +113,6 @@ if test "$enable_largefile" != no; then
       [Define for large files, on AIX-style hosts.],
       [_AC_SYS_LARGEFILE_TEST_INCLUDES])
   fi
-
-  AC_DEFINE([_DARWIN_USE_64_BIT_INODE], [1],
-    [Enable large inode numbers on Mac OS X 10.5.])
 fi
 ])# AC_SYS_LARGEFILE
 ])# m4_version_prereq 2.70