Change both IfThenTo... inspections highlight level

Retain WEAK WARNING for null checks, one-liners,
and is checks without dot calls in main branch.
Set INFORMATION (no highlighting, just fix) for other cases.

Switch off both bound intentions.
So #KT-15076 Fixed

idea/src/META-INF/plugin.xml

@@ -925,21 +925,11 @@
       <category>Kotlin</category>
     </intentionAction>
 
-    <intentionAction>
-      <className>org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions.IfThenToElvisIntention</className>
-      <category>Kotlin</category>
-    </intentionAction>
-
     <intentionAction>
       <className>org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions.SafeAccessToIfThenIntention</className>
       <category>Kotlin</category>
     </intentionAction>
 
-    <intentionAction>
-      <className>org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions.IfThenToSafeAccessIntention</className>
-      <category>Kotlin</category>
-    </intentionAction>
-
     <intentionAction>
       <className>org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions.IfToWhenIntention</className>
       <category>Kotlin</category>

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/IfThenUtils.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.idea.intentions.getLeftMostReceiverExpression
 import org.jetbrains.kotlin.idea.intentions.replaceFirstReceiver
 import org.jetbrains.kotlin.idea.refactoring.inline.KotlinInlineValHandler
 import org.jetbrains.kotlin.idea.refactoring.introduce.introduceVariable.KotlinIntroduceVariableHandler
+import org.jetbrains.kotlin.idea.refactoring.isMultiLine
 import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
@@ -201,6 +202,21 @@ internal fun KtIfExpression.buildSelectTransformationData(): IfThenToSelectData?
     return IfThenToSelectData(context, condition, receiverExpression, baseClause, negatedClause)
 }
 
+internal fun KtIfExpression.shouldBeTransformed(): Boolean {
+    val condition = condition
+    return when (condition) {
+        is KtBinaryExpression -> true
+        is KtIsExpression -> {
+            if (!isMultiLine()) true
+            else {
+                val baseClause = (if (condition.isNegated) `else` else then)?.unwrapBlockOrParenthesis()
+                baseClause !is KtDotQualifiedExpression
+            }
+        }
+        else -> false
+    }
+}
+
 private fun KtExpression.checkedExpression() = when (this) {
     is KtBinaryExpression -> expressionComparedToNull()
     is KtIsExpression -> leftHandSide

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions
 
+import com.intellij.codeInspection.ProblemHighlightType
 import com.intellij.openapi.editor.Editor
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
@@ -35,6 +36,9 @@ class IfThenToElvisInspection : IntentionBasedInspection<KtIfExpression>(
         { it -> it.isUsedAsExpression(it.analyze(BodyResolveMode.PARTIAL)) }
 ) {
     override fun inspectionTarget(element: KtIfExpression) = element.ifKeyword
+
+    override fun problemHighlightType(element: KtIfExpression): ProblemHighlightType =
+            if (element.shouldBeTransformed()) ProblemHighlightType.WEAK_WARNING else super.problemHighlightType(element)
 }
 
 class IfThenToElvisIntention : SelfTargetingOffsetIndependentIntention<KtIfExpression>(

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToSafeAccessIntention.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.idea.intentions.branchedTransformations.intentions
 
+import com.intellij.codeInspection.ProblemHighlightType
 import com.intellij.openapi.editor.Editor
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.idea.core.replaced
@@ -27,6 +28,9 @@ import org.jetbrains.kotlin.psi.*
 
 class IfThenToSafeAccessInspection : IntentionBasedInspection<KtIfExpression>(IfThenToSafeAccessIntention::class) {
     override fun inspectionTarget(element: KtIfExpression) = element.ifKeyword
+
+    override fun problemHighlightType(element: KtIfExpression): ProblemHighlightType =
+            if (element.shouldBeTransformed()) ProblemHighlightType.WEAK_WARNING else ProblemHighlightType.INFORMATION
 }
 
 class IfThenToSafeAccessIntention : SelfTargetingOffsetIndependentIntention<KtIfExpression>(