improve alignment autoconf test (#1129)

Replace the deprecated AC_TRY_RUN with AC_RUN_IFELSE. Also, standardize the
variable name and allow for caching of the result.

aclocal.m4

@@ -13,7 +13,7 @@
 
 m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
 dnl pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
-dnl serial 11 (pkg-config-0.29)
+dnl serial 11 (pkg-config-0.29.1)
 dnl
 dnl Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
 dnl Copyright © 2012-2015 Dan Nicholson <dbn.lists@gmail.com>
@@ -55,7 +55,7 @@ dnl
 dnl See the "Since" comment for each macro you use to see what version
 dnl of the macros you require.
 m4_defun([PKG_PREREQ],
-[m4_define([PKG_MACROS_VERSION], [0.29])
+[m4_define([PKG_MACROS_VERSION], [0.29.1])
 m4_if(m4_version_compare(PKG_MACROS_VERSION, [$1]), -1,
     [m4_fatal([pkg.m4 version $1 or higher is required but ]PKG_MACROS_VERSION[ found])])
 ])dnl PKG_PREREQ

configure

@@ -784,6 +784,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -894,6 +895,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1146,6 +1148,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1283,7 +1294,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1436,6 +1447,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -9738,8 +9750,11 @@ esac
 # check for systems that require aligned memory access
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking aligned memory access is required" >&5
 $as_echo_n "checking aligned memory access is required... " >&6; }
-if test "$cross_compiling" = yes; then :
+if ${ac_cv_aligned_required+:} false; then :
-  aligned_required=yes
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  ac_cv_aligned_required=yes
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -9756,26 +9771,26 @@ int main()
         return 1;
     return 0;
 }
-
 _ACEOF
 if ac_fn_c_try_run "$LINENO"; then :
-  aligned_required=no
+  ac_cv_aligned_required=no
 else
-  aligned_required=yes
+  ac_cv_aligned_required=yes
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
   conftest.$ac_objext conftest.beam conftest.$ac_ext
 fi
 
 
-if test "$aligned_required" = yes ; then
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_aligned_required" >&5
+$as_echo "$ac_cv_aligned_required" >&6; }
+if test "$ac_cv_aligned_required" = yes ; then
 
 $as_echo "#define HAVE_ALIGNED_REQUIRED 1" >>confdefs.h
 
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $aligned_required" >&5
-$as_echo "$aligned_required" >&6; }
-
 
 # str, bytes and memoryview hash algorithm
 

configure.ac

@@ -2716,7 +2716,8 @@ esac
 
 # check for systems that require aligned memory access
 AC_MSG_CHECKING(aligned memory access is required)
-AC_TRY_RUN([
+AC_CACHE_VAL(ac_cv_aligned_required,
+[AC_RUN_IFELSE([AC_LANG_SOURCE([[
 int main()
 {
     char s[16];
@@ -2728,18 +2729,16 @@ int main()
     if (*p1 == *p2)
         return 1;
     return 0;
-}
+}]])],
-              ],
+[ac_cv_aligned_required=no],
-     [aligned_required=no],
+[ac_cv_aligned_required=yes],
-     [aligned_required=yes],
+[ac_cv_aligned_required=yes])
-     [aligned_required=yes])
+])
-
+AC_MSG_RESULT($ac_cv_aligned_required)
-if test "$aligned_required" = yes ; then
+if test "$ac_cv_aligned_required" = yes ; then
   AC_DEFINE([HAVE_ALIGNED_REQUIRED], [1],
     [Define if aligned memory access is required])
 fi
-AC_MSG_RESULT($aligned_required)
-
 
 # str, bytes and memoryview hash algorithm
 AH_TEMPLATE(Py_HASH_ALGORITHM,