Use "if-then to" even for 'if (arg != null) arg' removing 'if'

idea/testData/intentions/branched/ifThenToSafeAccess/inspectionData/expected.xml

@@ -135,4 +135,12 @@
     <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?.'</problem_class>
     <description>Replace 'if' expression with safe cast expression</description>
   </problem>
+  <problem>
+    <file>nullCheckSimple.kt</file>
+    <line>2</line>
+    <module>light_idea_test_case</module>
+    <entry_point TYPE="file" FQNAME="temp:///src/nullCheckSimple.kt" />
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">If-Then foldable to '?.'</problem_class>
+    <description>Remove redundant 'if' expression</description>
+  </problem>
 </problems>

idea/testData/intentions/branched/ifThenToSafeAccess/nullCheckSimple.kt

@@ -1,5 +1,3 @@
-// IS_APPLICABLE: false
-
 fun foo(arg: Any?): Any? {
     return if (<caret>arg != null) arg else null
 }

idea/testData/intentions/branched/ifThenToSafeAccess/nullCheckSimple.kt.after

@@ -0,0 +1,3 @@
+fun foo(arg: Any?): Any? {
+    return arg
+}