fix duplicate stubs after multi-root file rename

either stubs from all roots should be cleared, or none, but not just one
let's try "none" because we don't clear AST anyway

platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java

@@ -433,7 +433,6 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
   @Override
   public PsiElement setName(@NotNull String name) throws IncorrectOperationException {
     checkSetName(name);
-    doClearCaches("setName");
     return PsiFileImplUtil.setName(this, name);
   }