make 'SolverChecker' singleton (#1386)

Author: dbinkele

code/languages/org.iets3.opensource/languages/org.iets3.analysis.base/models/plugin.mps

@@ -5148,17 +5148,16 @@
       <node concept="3clFbS" id="2f_Mi5n7Ldp" role="2VODD2">
         <node concept="3clFbF" id="2f_Mi5n7QNu" role="3cqZAp">
           <node concept="37vLTI" id="2f_Mi5n7Rqk" role="3clFbG">
-            <node concept="2ShNRf" id="2f_Mi5n7RqO" role="37vLTx">
-              <node concept="HV5vD" id="2f_Mi5n7RW1" role="2ShVmc">
-                <ref role="HV5vE" node="2f_Mi5n7Neo" resolve="SolverChecker" />
-              </node>
-            </node>
             <node concept="2OqwBi" id="2f_Mi5n7QXY" role="37vLTJ">
               <node concept="2WthIp" id="2f_Mi5n7QNs" role="2Oq$k0" />
               <node concept="2BZ7hE" id="2f_Mi5n7R9u" role="2OqNvi">
                 <ref role="2WH_rO" node="2f_Mi5n7Q1c" resolve="checker" />
               </node>
             </node>
+            <node concept="2YIFZM" id="3p6vP4htZS0" role="37vLTx">
+              <ref role="37wK5l" node="50SLpTeAUQv" resolve="instance" />
+              <ref role="1Pybhc" node="2f_Mi5n7Neo" resolve="SolverChecker" />
+            </node>
           </node>
         </node>
         <node concept="3cpWs8" id="7uM3WAark3_" role="3cqZAp">
@@ -5244,6 +5243,21 @@
   <node concept="312cEu" id="2f_Mi5n7Neo">
     <property role="TrG5h" value="SolverChecker" />
     <property role="3GE5qa" value="AsyncISolvable" />
+    <node concept="2tJIrI" id="50SLpTe_dSb" role="jymVt" />
+    <node concept="Wx3nA" id="50SLpTe_Jh2" role="jymVt">
+      <property role="TrG5h" value="instance" />
+      <property role="3TUv4t" value="true" />
+      <node concept="3uibUv" id="50SLpTe_Jh5" role="1tU5fm">
+        <ref role="3uigEE" node="2f_Mi5n7Neo" resolve="SolverChecker" />
+      </node>
+      <node concept="3Tm6S6" id="50SLpTe_Jh4" role="1B3o_S" />
+      <node concept="2ShNRf" id="50SLpTe_L0c" role="33vP2m">
+        <node concept="1pGfFk" id="50SLpTeDzXk" role="2ShVmc">
+          <ref role="37wK5l" node="50SLpTeDzdC" resolve="SolverChecker" />
+        </node>
+      </node>
+    </node>
+    <node concept="2tJIrI" id="50SLpTeALIK" role="jymVt" />
     <node concept="312cEg" id="5lWcBwKPvxe" role="jymVt">
       <property role="TrG5h" value="changeCounts" />
       <node concept="3Tm6S6" id="5lWcBwKPvxf" role="1B3o_S" />
@@ -5268,13 +5282,34 @@
       </node>
     </node>
     <node concept="2tJIrI" id="3K_gMq6RgTa" role="jymVt" />
-    <node concept="2tJIrI" id="3K_gMq6RgVp" role="jymVt" />
+    <node concept="3clFbW" id="50SLpTeDzdC" role="jymVt">
+      <node concept="3cqZAl" id="50SLpTeDzdE" role="3clF45" />
+      <node concept="3Tm6S6" id="3p6vP4hu2LH" role="1B3o_S" />
+      <node concept="3clFbS" id="50SLpTeDzdG" role="3clF47" />
+    </node>
+    <node concept="2tJIrI" id="50SLpTeDQsT" role="jymVt" />
+    <node concept="2YIFZL" id="50SLpTeAUQv" role="jymVt">
+      <property role="TrG5h" value="instance" />
+      <node concept="3clFbS" id="50SLpTeAUQz" role="3clF47">
+        <node concept="3clFbF" id="50SLpTeAUQ$" role="3cqZAp">
+          <node concept="37vLTw" id="50SLpTeAUQ_" role="3clFbG">
+            <ref role="3cqZAo" node="50SLpTe_Jh2" resolve="instance" />
+          </node>
+        </node>
+      </node>
+      <node concept="3uibUv" id="50SLpTeAUQx" role="3clF45">
+        <ref role="3uigEE" node="2f_Mi5n7Neo" resolve="SolverChecker" />
+      </node>
+      <node concept="3Tm1VV" id="50SLpTeAUQy" role="1B3o_S" />
+    </node>
+    <node concept="2tJIrI" id="50SLpTeARat" role="jymVt" />
     <node concept="3Tm1VV" id="2f_Mi5n7Nep" role="1B3o_S" />
     <node concept="3uibUv" id="2f_Mi5n7NWO" role="1zkMxy">
       <ref role="3uigEE" to="n70j:~BaseEditorChecker" resolve="BaseEditorChecker" />
     </node>
     <node concept="3clFb_" id="2f_Mi5n7O6a" role="jymVt">
       <property role="TrG5h" value="needsUpdate" />
+      <property role="od$2w" value="true" />
       <node concept="3Tm1VV" id="2f_Mi5n7O6b" role="1B3o_S" />
       <node concept="10P_77" id="2f_Mi5n7O6d" role="3clF45" />
       <node concept="37vLTG" id="2f_Mi5n7O6e" role="3clF46">