[java-inspections] PatternVariableCanBeUsed: equivalence check should be performed in narrowing cast as well

Fixes IDEA-348779 "Pattern variable can be used" inspection false positive

GitOrigin-RevId: a1ac8fe39011db2127d8d6d627cfae913320995a

java/java-analysis-impl/src/com/siyeh/ig/psiutils/InstanceOfUtils.java

@@ -360,12 +360,11 @@ public final class InstanceOfUtils {
         PsiType type = typeElement.getType();
         PsiType castType = Objects.requireNonNull(cast.getCastType()).getType();
         PsiExpression castOperand = Objects.requireNonNull(cast.getOperand());
-        if (typeCompatible(type, castType, castOperand) &&
-            PsiEquivalenceUtil.areElementsEquivalent(instanceOf.getOperand(), castOperand)) {
-          return instanceOf;
-        }
-        if (PsiUtil.isJvmLocalVariable(variable) && isSafeToNarrowType(variable, cast, type)) {
-          return instanceOf;
+        if (PsiEquivalenceUtil.areElementsEquivalent(instanceOf.getOperand(), castOperand)) {
+          if (typeCompatible(type, castType, castOperand) ||
+              PsiUtil.isJvmLocalVariable(variable) && isSafeToNarrowType(variable, cast, type)) {
+            return instanceOf;
+          }
         }
       }
     }

java/java-tests/testData/inspection/patternVariableCanBeUsed/beforeWrongVariable.java

@@ -0,0 +1,10 @@
+// "Replace 'number' with pattern variable" "false"
+class X {
+  public static void main(String[] args) {
+    Object o1 = 1.0;
+    Object o2 = 2;
+    if (!(o1 instanceof Double)) return;
+    Number n<caret>umber = (Number) o2;
+    System.out.println("number = " + number);
+  }
+}