safe delete: do not change semantic on delete loop/if body (IDEA-114406)

java/java-tests/testData/refactoring/safeDelete/EmptyIf.java

@@ -0,0 +1,8 @@
+class A {
+    void f(String p){
+        String <caret>t;
+        if (p == null)
+            t = "1";
+        System.out.println("");
+    }
+}

java/java-tests/testData/refactoring/safeDelete/EmptyIf_after.java

@@ -0,0 +1,7 @@
+class A {
+    void f(String p){
+        if (p == null)
+            ;
+        System.out.println("");
+    }
+}