Use <stdint.h> and <inttypes.h> for c.h integers.

Redefine our exact width types with standard C99 types and macros,
including int64_t, INT64_MAX, INT64_C(), PRId64 etc.  We were already
using <stdint.h> types in a few places.

One complication is that Windows' <inttypes.h> uses format strings like
"%I64d", "%I32", "%I" for PRI*64, PRI*32, PTR*PTR, instead of mapping to
other standardized format strings like "%lld" etc as seen on other known
systems.  Teach our snprintf.c to understand them.

This removes a lot of configure clutter, and should also allow 64-bit
numbers and other standard types to be used in localized messages
without casting.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/ME3P282MB3166F9D1F71F787929C0C7E7B6312%40ME3P282MB3166.AUSP282.PROD.OUTLOOK.COM

configure.ac

@@ -1604,6 +1604,7 @@ PGAC_C_STATIC_ASSERT
 PGAC_C_TYPEOF
 PGAC_C_TYPES_COMPATIBLE
 PGAC_C_BUILTIN_CONSTANT_P
+PGAC_C_BUILTIN_OP_OVERFLOW
 PGAC_C_BUILTIN_UNREACHABLE
 PGAC_C_COMPUTED_GOTO
 PGAC_STRUCT_TIMEZONE
@@ -1906,54 +1907,18 @@ for the exact reason.]])],
 # Run tests below here
 # --------------------
 
-dnl Check to see if we have a working 64-bit integer type.
-dnl Since Postgres 8.4, we no longer support compilers without a working
-dnl 64-bit type; but we have to determine whether that type is called
-dnl "long int" or "long long int".
-
-PGAC_TYPE_64BIT_INT([long int])
-
-if test x"$HAVE_LONG_INT_64" = x"yes" ; then
-  pg_int64_type="long int"
-else
-  PGAC_TYPE_64BIT_INT([long long int])
-  if test x"$HAVE_LONG_LONG_INT_64" = x"yes" ; then
-    pg_int64_type="long long int"
-  else
-    AC_MSG_ERROR([Cannot find a working 64-bit integer type.])
-  fi
-fi
-
-AC_DEFINE_UNQUOTED(PG_INT64_TYPE, $pg_int64_type,
-  [Define to the name of a signed 64-bit integer type.])
-
-# Select the printf length modifier that goes with that, too.
-if test x"$pg_int64_type" = x"long long int" ; then
-  INT64_MODIFIER='"ll"'
-else
-  INT64_MODIFIER='"l"'
-fi
-
-AC_DEFINE_UNQUOTED(INT64_MODIFIER, $INT64_MODIFIER,
-                   [Define to the appropriate printf length modifier for 64-bit ints.])
-
-# has to be down here, rather than with the other builtins, because
-# the test uses PG_INT64_TYPE.
-PGAC_C_BUILTIN_OP_OVERFLOW
-
 # Check size of void *, size_t (enables tweaks for > 32bit address space)
 AC_CHECK_SIZEOF([void *])
 AC_CHECK_SIZEOF([size_t])
 AC_CHECK_SIZEOF([long])
+AC_CHECK_SIZEOF([long long])
 
 # Determine memory alignment requirements for the basic C data types.
 
 AC_CHECK_ALIGNOF(short)
 AC_CHECK_ALIGNOF(int)
 AC_CHECK_ALIGNOF(long)
-if test x"$HAVE_LONG_LONG_INT_64" = x"yes" ; then
-  AC_CHECK_ALIGNOF(long long int)
-fi
+AC_CHECK_ALIGNOF(int64_t)
 AC_CHECK_ALIGNOF(double)
 
 # Compute maximum alignment of any basic type.
@@ -1977,12 +1942,11 @@ MAX_ALIGNOF=$ac_cv_alignof_double
 if test $ac_cv_alignof_long -gt $MAX_ALIGNOF ; then
   AC_MSG_ERROR([alignment of 'long' is greater than the alignment of 'double'])
 fi
-if test x"$HAVE_LONG_LONG_INT_64" = xyes && test $ac_cv_alignof_long_long_int -gt $MAX_ALIGNOF ; then
-  AC_MSG_ERROR([alignment of 'long long int' is greater than the alignment of 'double'])
+if test $ac_cv_alignof_int64_t -gt $MAX_ALIGNOF ; then
+  AC_MSG_ERROR([alignment of 'int64_t' is greater than the alignment of 'double'])
 fi
 AC_DEFINE_UNQUOTED(MAXIMUM_ALIGNOF, $MAX_ALIGNOF, [Define as the maximum alignment requirement of any C data type.])
 
-
 # Some compilers offer a 128-bit integer scalar type.
 PGAC_TYPE_128BIT_INT
 
@@ -2472,12 +2436,6 @@ AC_CONFIG_HEADERS([src/include/pg_config.h],
 echo >src/include/stamp-h
 ])
 
-AC_CONFIG_HEADERS([src/include/pg_config_ext.h],
-[
-# Update timestamp for pg_config_ext.h (see Makefile.global)
-echo >src/include/stamp-ext-h
-])
-
 AC_CONFIG_HEADERS([src/interfaces/ecpg/include/ecpg_config.h],
                   [echo >src/interfaces/ecpg/include/stamp-h])