[GR-61239] Fix BuildPhaseProvider.is*Finished() so that these methods…

… can be used at any time during the image build.

PullRequest: graal/19804

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/BuildPhaseProvider.java

@@ -65,47 +65,47 @@ public static void markAnalysisFinished() {
     }
 
     public static boolean isAnalysisFinished() {
-        return singleton().analysisFinished;
+        return ImageSingletons.contains(BuildPhaseProvider.class) && singleton().analysisFinished;
     }
 
     public static void markHostedUniverseBuilt() {
         singleton().hostedUniverseBuilt = true;
     }
 
     public static boolean isHostedUniverseBuilt() {
-        return singleton().hostedUniverseBuilt;
+        return ImageSingletons.contains(BuildPhaseProvider.class) && singleton().hostedUniverseBuilt;
     }
 
     public static void markReadyForCompilation() {
         singleton().readyForCompilation = true;
     }
 
     public static boolean isReadyForCompilation() {
-        return singleton().readyForCompilation;
+        return ImageSingletons.contains(BuildPhaseProvider.class) && singleton().readyForCompilation;
     }
 
     public static void markCompileQueueFinished() {
         singleton().compileQueueFinished = true;
     }
 
     public static boolean isCompileQueueFinished() {
-        return singleton().compileQueueFinished;
+        return ImageSingletons.contains(BuildPhaseProvider.class) && singleton().compileQueueFinished;
     }
 
     public static void markCompilationFinished() {
         singleton().compilationFinished = true;
     }
 
     public static boolean isCompilationFinished() {
-        return singleton().compilationFinished;
+        return ImageSingletons.contains(BuildPhaseProvider.class) && singleton().compilationFinished;
     }
 
     public static void markHeapLayoutFinished() {
         singleton().heapLayoutFinished = true;
     }
 
     public static boolean isHeapLayoutFinished() {
-        return singleton().heapLayoutFinished;
+        return ImageSingletons.contains(BuildPhaseProvider.class) && singleton().heapLayoutFinished;
     }
 
     public static class AfterAnalysis implements BooleanSupplier {