IDEA-130782 make RemoveUnusedVariableUtil#checkSideEffects Contract(pure) aware

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/after7.java

@@ -4,7 +4,8 @@ import java.io.*;
 class a {
     int k;
     private void run() {
-        <caret>while (1 > 0) ;
+        k = 9;
+        while (1 > 0) ;
         for (;; ) ;
     }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterPure.java

@@ -0,0 +1,13 @@
+// "Remove variable 'i'" "true"
+import org.jetbrains.annotations.Contract;
+
+class a {
+    private void run() {
+    }
+
+  @Contract(pure = true)
+  private Object dodo() {
+    return null;
+  }
+}
+

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforePure.java

@@ -0,0 +1,14 @@
+// "Remove variable 'i'" "true"
+import org.jetbrains.annotations.Contract;
+
+class a {
+    private void run() {
+        Object <caret>i = dodo();
+    }
+
+  @Contract(pure = true)
+  private Object dodo() {
+    return null;
+  }
+}
+