Fix minor compile warnings

compiler/psi/src/org/jetbrains/kotlin/kdoc/parser/KDocKnownTag.kt

@@ -16,8 +16,6 @@
 
 package org.jetbrains.kotlin.kdoc.parser
 
-import com.intellij.openapi.util.text.StringUtil
-
 enum class KDocKnownTag(val isReferenceRequired: Boolean, val isSectionStart: Boolean) {
     AUTHOR(false, false),
     THROWS(true, false),
@@ -35,12 +33,11 @@ enum class KDocKnownTag(val isReferenceRequired: Boolean, val isSectionStart: Bo
 
     companion object {
         fun findByTagName(tagName: CharSequence): KDocKnownTag? {
-            var tagName = tagName
-            if (StringUtil.startsWith(tagName, "@")) {
-                tagName = tagName.subSequence(1, tagName.length)
-            }
+            val name = if (tagName.startsWith('@')) {
+                tagName.subSequence(1, tagName.length)
+            } else tagName
             try {
-                return valueOf(tagName.toString().toUpperCase())
+                return valueOf(name.toString().toUpperCase())
             } catch (ignored: IllegalArgumentException) {
             }
 

compiler/psi/src/org/jetbrains/kotlin/psi/EditCommaSeparatedListHelper.kt

@@ -28,6 +28,7 @@ object EditCommaSeparatedListHelper {
         return addItemBefore(list, allItems, item, null, prefix)
     }
 
+    @Suppress("UNCHECKED_CAST")
     @JvmOverloads
     fun <TItem : KtElement> addItemAfter(
         list: KtElement,

compiler/psi/src/org/jetbrains/kotlin/psi/KtPsiFactory.kt

@@ -292,6 +292,7 @@ class KtPsiFactory @JvmOverloads constructor(private val project: Project, val m
         val file = createFile(text)
         val declarations = file.declarations
         assert(declarations.size == 1) { "${declarations.size} declarations in $text" }
+        @Suppress("UNCHECKED_CAST")
         return declarations.first() as TDeclaration
     }