configure.ac (ACX_PROG_GNAT): Append "libgnat" to the include dir.

	* configure.ac (ACX_PROG_GNAT): Append "libgnat" to the include dir.
	* configure: Regenerate.

From-SVN: r253928

gcc/ChangeLog

+2017-10-20  Nicolas Roche  <roche@adacore.com>
+
+	* configure.ac (ACX_PROG_GNAT): Append "libgnat" to the include dir.
+	* configure: Regenerate.
+
 2017-10-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/82158

gcc/configure

@@ -4987,7 +4987,7 @@ acx_cv_cc_gcc_supports_ada=no
 # Other compilers, like HP Tru64 UNIX cc, exit successfully when
 # given a .adb file, but produce no object file.  So we must check
 # if an object file was really produced to guard against this.
-errors=`(${CC} -I"$srcdir"/ada -c conftest.adb) 2>&1 || echo failure`
+errors=`(${CC} -I"$srcdir"/ada/libgnat -c conftest.adb) 2>&1 || echo failure`
 if test x"$errors" = x && test -f conftest.$ac_objext; then
   acx_cv_cc_gcc_supports_ada=yes
 fi

gcc/configure.ac

@@ -362,7 +362,7 @@ rm -f a.out a.exe b.out
 # Find the native compiler
 AC_PROG_CC
 AC_PROG_CXX
-ACX_PROG_GNAT([-I"$srcdir"/ada])
+ACX_PROG_GNAT([-I"$srcdir"/ada/libgnat])
 
 # Do configure tests with the C++ compiler, since that's what we build with.
 AC_LANG(C++)