GCN libgfortran.

This patch contains the GCN port of libgfortran.  We use the minimal
configuration created for NVPTX.  That's all that's required, besides the
target-independent bug fixes posted already.

2019-01-17  Andrew Stubbs  <ams@codesourcery.com>
	    Kwok Cheung Yeung  <kcy@codesourcery.com>
	    Julian Brown  <julian@codesourcery.com>
	    Tom de Vries  <tom@codesourcery.com>

	libgfortran/
	* configure.ac: Use minimal mode for amdgcn.
	* configure: Regenerate.


Co-Authored-By: Julian Brown <julian@codesourcery.com>
Co-Authored-By: Kwok Cheung Yeung <kcy@codesourcery.com>
Co-Authored-By: Tom de Vries <tom@codesourcery.com>

From-SVN: r268020

libgfortran/ChangeLog

+2019-01-17  Andrew Stubbs  <ams@codesourcery.com>
+	    Kwok Cheung Yeung  <kcy@codesourcery.com>
+	    Julian Brown  <julian@codesourcery.com>
+	    Tom de Vries  <tom@codesourcery.com>
+
+	* configure.ac: Use minimal mode for amdgcn.
+	* configure: Regenerate.
+
 2019-01-13  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libfortran/88776

libgfortran/configure

@@ -6164,7 +6164,8 @@ fi
 # * C library support for other features such as signal, environment
 #   variables, time functions
 
- if test "x${target_cpu}" = xnvptx; then
+ if test "x${target_cpu}" = xnvptx \
+				 || test "x${target_cpu}" = xamdgcn; then
   LIBGFOR_MINIMAL_TRUE=
   LIBGFOR_MINIMAL_FALSE='#'
 else
@@ -12684,7 +12685,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12687 "configure"
+#line 12688 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12790,7 +12791,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12793 "configure"
+#line 12794 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H

libgfortran/configure.ac

@@ -205,7 +205,8 @@ AM_CONDITIONAL(LIBGFOR_USE_SYMVER_SUN, [test "x$gfortran_use_symver" = xsun])
 # * C library support for other features such as signal, environment
 #   variables, time functions
 
-AM_CONDITIONAL(LIBGFOR_MINIMAL, [test "x${target_cpu}" = xnvptx])
+AM_CONDITIONAL(LIBGFOR_MINIMAL, [test "x${target_cpu}" = xnvptx \
+				 || test "x${target_cpu}" = xamdgcn])
 
 # Figure out whether the compiler supports "-ffunction-sections -fdata-sections",
 # similarly to how libstdc++ does it