Refined the --enable-languages so that cobol doesn't add a second c++

configure

@@ -3548,11 +3548,15 @@ esac
 # Otherwise, enable COBOL only for known architectures
 case ,${enable_languages}, in
   *,cobol,*)
-    # We know there is an explicit "cobol" in "enable_languages"
-    # Make sure c++ is in the list of languages so that a --disable-bootstrap
-    # build works.  (cobol requires the stdc++ library, so we need to build
-    # gcc).  If c++ is already there, adding again is harmless.
-	enable_languages="$enable_languages,c++"
+    case ,${enable_languages}, in
+      *,c++,*)
+      ;;
+      *)
+        # We have an explicit cobol, but no c++.  We need c++, because cobol
+        # requires libstdc++
+        enable_languages="$enable_languages,c++"
+      ;;
+    esac
     ;;
   *)
     case "${target}" in
@@ -3566,8 +3570,8 @@ case ,${enable_languages}, in
       x86_64-*-*|aarch64-*-*)
         ;;
       *-*-*)
-	unsupported_languages="$unsupported_languages cobol"
-	;;
+    unsupported_languages="$unsupported_languages cobol"
+    ;;
     esac
     ;;
 esac

configure.ac

@@ -768,26 +768,30 @@ esac
 # Otherwise, enable COBOL only for known architectures
 case ,${enable_languages}, in
   *,cobol,*)
-    # We know there is an explicit "cobol" in "enable_languages"
-    # Make sure c++ is in the list of languages so that a --disable-bootstrap
-    # build works.  (cobol requires the stdc++ library, so we need to build
-    # gcc).  If c++ is already there, adding again is harmless.
-	enable_languages="$enable_languages,c++"
+    case ,${enable_languages}, in
+      *,c++,*)
+      ;;
+      *)
+        # We have an explicit cobol, but no c++.  We need c++, because cobol
+        # requires libstdc++
+        enable_languages="$enable_languages,c++"
+      ;;
+    esac
     ;;
   *)
     case "${target}" in
       x86_64-*-*|aarch64-*-*)
         ;;
       *-*-*)
-	unsupported_languages="$unsupported_languages cobol"
-	;;
+    unsupported_languages="$unsupported_languages cobol"
+    ;;
     esac
     case "${host}" in
       x86_64-*-*|aarch64-*-*)
         ;;
       *-*-*)
-	unsupported_languages="$unsupported_languages cobol"
-	;;
+    unsupported_languages="$unsupported_languages cobol"
+    ;;
     esac
     ;;
 esac