Merge branch 'maint'

* maint:
  tests: avoid spurious failure on missing Obj C/C++ compiler
  objc, objc++: test support for compilation flags
  objc, objc++: add stress test
  objc, objc++: test automatic dependency tracking
  objc: reorganize basic tests
  objc++, objc: add first semantic tests
  objc++: add first basic test
  news: announce initial support for Objective C++
  objc++: test support for '.mm' suffix in _SOURCES entries
  objc++: add documentation
  objc++: initial support for Objective C++

diff --cc NEWS
Simple merge

diff --cc automake.in
Simple merge

diff --cc doc/automake.texi
Simple merge

diff --cc m4/init.m4
index 9731527,0cf8720..9db4eea
--- 1/m4/init.m4
--- 2/m4/init.m4
+++ b/m4/init.m4
@@@ -100,8 -100,15 +100,15 @@@ AC_PROVIDE_IFELSE([AC_PROG_OBJC]
                  [_AM_DEPENDENCIES([OBJC])],
                  [define([AC_PROG_OBJC],
                          defn([AC_PROG_OBJC])[_AM_DEPENDENCIES([OBJC])])])dnl
+ dnl Support for Objective C++ was only introduced in Autoconf 2.65,
+ dnl but we still cater to Autoconf 2.62.
+ m4_ifdef([AC_PROG_OBJCXX],
+ [AC_PROVIDE_IFELSE([AC_PROG_OBJCXX],
+                 [_AM_DEPENDENCIES([OBJCXX])],
+                 [define([AC_PROG_OBJCXX],
+                         defn([AC_PROG_OBJCXX])[_AM_DEPENDENCIES([OBJCXX])])])])dnl
  ])
 -_AM_IF_OPTION([silent-rules], [AC_REQUIRE([AM_SILENT_RULES])])dnl
 +AC_REQUIRE([AM_SILENT_RULES])dnl
  dnl The 'parallel-tests' driver may need to know about EXEEXT, so add the
  dnl 'am__EXEEXT' conditional if _AM_COMPILER_EXEEXT was seen.  This macro
  dnl is hooked onto _AC_COMPILER_EXEEXT early, see below.

diff --cc t/list-of-tests.mk
index 3ff1c2c,708e972..ecb5bf2
--- 1/t/list-of-tests.mk
--- 2/t/list-of-tests.mk
+++ b/t/list-of-tests.mk
@@@ -694,9 -703,17 +694,16 @@@ t/nolink.sh 
  t/nostdinc.sh \
  t/notrans.sh \
  t/number.sh \
- t/objc.sh \
- t/objc2.sh \
+ t/objc-basic.sh \
+ t/objc-minidemo.sh \
+ t/objc-flags.sh \
+ t/objc-deps.sh \
+ t/objcxx-basic.sh \
+ t/objcxx-minidemo.sh \
+ t/objcxx-flags.sh \
+ t/objcxx-deps.sh \
+ t/objc-megademo.sh \
  t/objext-pr10128.sh \
 -t/obsolete.sh \
  t/oldvars.sh \
  t/order.sh \
  t/output.sh \