AstLoadingFilter: allow enabling loading for a file before disabling it

platform/core-api/src/com/intellij/util/AstLoadingFilter.java

@@ -144,9 +144,6 @@ public class AstLoadingFilter {
 
   public static <T, E extends Throwable>
   T forceEnableTreeLoading(@NotNull VirtualFile virtualFile, @NotNull ThrowableComputable<T, E> computable) throws E {
-    if (myDisabledInfo.get() == null) {
-      throw new IllegalStateException("It's not allowed to force enable loading before it has been disabled");
-    }
     Set<VirtualFile> enabledFiles = myForcedEnabledFiles.get();
     if (enabledFiles.add(virtualFile)) {
       try {

platform/platform-tests/testSrc/com/intellij/util/AstLoadingFilterTest.java

@@ -89,20 +89,4 @@ public class AstLoadingFilterTest extends LightPlatformCodeInsightFixtureTestCas
       )
     ));
   }
-
-  public void testForceEnableLoadingBeforeDisabling() throws Throwable {
-    PsiFileImpl file = addFile();
-    assertFalse(file.isContentsLoaded());
-    assertException(new AbstractExceptionCase<IllegalStateException>() {
-      @Override
-      public Class<IllegalStateException> getExpectedExceptionClass() {
-        return IllegalStateException.class;
-      }
-
-      @Override
-      public void tryClosure() throws IllegalStateException {
-        forceEnableTreeLoading(file, () -> file.getNode());
-      }
-    });
-  }
 }