Minor, fix warnings on new stdlib API

In modules where allWarningsAsErrors is not yet enabled.

compiler/util-klib/src/org/jetbrains/kotlin/library/encodings/WobblyTF8.kt

@@ -29,11 +29,11 @@ object WobblyTF8 {
             if (char1 < '\u0080') {
                 // U+0000..U+007F -> 0xxxxxxx
                 // 7 meaningful bits -> 1 byte
-                buffer[writtenBytes++] = char1.toInt()
+                buffer[writtenBytes++] = char1.code
             } else if (char1 < '\u0800') {
                 // U+0080..U+07FF -> 110xxxxx 10xxxxxx
                 // 11 meaningful bits -> 2 bytes
-                val codePoint = char1.toInt()
+                val codePoint = char1.code
                 buffer[writtenBytes++] = (codePoint ushr 6) or 0b1100_0000
                 buffer[writtenBytes++] = (codePoint and 0b0011_1111) or 0b1000_0000
             } else {
@@ -55,7 +55,7 @@ object WobblyTF8 {
 
                 // U+0800..U+FFFF -> 1110xxxx 10xxxxxx 10xxxxxx
                 // 16 meaningful bits -> 3 bytes
-                val codePoint = char1.toInt()
+                val codePoint = char1.code
                 buffer[writtenBytes++] = (codePoint ushr 12) or 0b1110_0000
                 buffer[writtenBytes++] = ((codePoint ushr 6) and 0b0011_1111) or 0b1000_0000
                 buffer[writtenBytes++] = (codePoint and 0b0011_1111) or 0b1000_0000

compiler/util-klib/test/org/jetbrains/kotlin/library/encodings/WobblyTF8Test.kt

@@ -152,9 +152,9 @@ class WobblyTF8Test {
         fun ByteArray.decodeWithWobbly(): String = WobblyTF8.decode(this)
         fun ByteArray.decodeWithUTF8(): String = toString(Charsets.UTF_8)
 
-        val CODE_POINTS_BEFORE_SURROGATES = MIN_CODE_POINT until MIN_SURROGATE.toInt()
+        val CODE_POINTS_BEFORE_SURROGATES = MIN_CODE_POINT until MIN_SURROGATE.code
-        val CODE_POINTS_SURROGATES = MIN_SURROGATE.toInt()..MAX_SURROGATE.toInt()
+        val CODE_POINTS_SURROGATES = MIN_SURROGATE.code..MAX_SURROGATE.code
-        val CODE_POINTS_AFTER_SURROGATES = (MAX_SURROGATE.toInt() + 1) until MIN_SUPPLEMENTARY_CODE_POINT
+        val CODE_POINTS_AFTER_SURROGATES = (MAX_SURROGATE.code + 1) until MIN_SUPPLEMENTARY_CODE_POINT
         val CODE_POINTS_SUPPLEMENTARY = MIN_SUPPLEMENTARY_CODE_POINT..MAX_CODE_POINT
 
         fun generateWellFormedString(

idea/idea-frontend-fir/idea-frontend-fir-generator/src/org/jetbrains/kotlin/idea/frontend/api/fir/generator/HLDiagnosticConverter.kt

@@ -58,10 +58,10 @@ object HLDiagnosticConverter {
     }
 
     private fun DiagnosticData.getHLDiagnosticClassName() =
-        name.toLowerCase()
+        name.lowercase()
             .split('_')
             .joinToString(separator = "") {
-                it.capitalize()
+                it.replaceFirstChar(Char::uppercaseChar)
             }
 
     private fun DiagnosticData.getHLDiagnosticImplClassName() =

libraries/kotlinx-metadata/src/kotlinx/metadata/impl/readUtils.kt

@@ -37,7 +37,7 @@ fun ProtoBuf.Annotation.Argument.Value.readAnnotationArgument(strings: NameResol
 
     return when (type) {
         BYTE -> KmAnnotationArgument.ByteValue(intValue.toByte())
-        CHAR -> KmAnnotationArgument.CharValue(intValue.toChar())
+        CHAR -> KmAnnotationArgument.CharValue(intValue.toInt().toChar())
         SHORT -> KmAnnotationArgument.ShortValue(intValue.toShort())
         INT -> KmAnnotationArgument.IntValue(intValue.toInt())
         LONG -> KmAnnotationArgument.LongValue(intValue)

libraries/kotlinx-metadata/src/kotlinx/metadata/impl/writeUtils.kt

@@ -34,7 +34,7 @@ fun KmAnnotationArgument.writeAnnotationArgument(strings: StringTable): ProtoBuf
             }
             is KmAnnotationArgument.CharValue -> {
                 this.type = ProtoBuf.Annotation.Argument.Value.Type.CHAR
-                this.intValue = value.toLong()
+                this.intValue = value.code.toLong()
             }
             is KmAnnotationArgument.ShortValue -> {
                 this.type = ProtoBuf.Annotation.Argument.Value.Type.SHORT

libraries/stdlib/js/src/kotlin/text/stringsCode.kt

@@ -85,7 +85,7 @@ public actual fun CharSequence.regionMatches(thisOffset: Int, other: CharSequenc
 @Deprecated("Use replaceFirstChar instead.", ReplaceWith("replaceFirstChar { if (it.isLowerCase()) it.titlecase() else it.toString() }"))
 @DeprecatedSinceKotlin(warningSince = "1.5")
 public actual fun String.capitalize(): String {
-    return if (isNotEmpty()) substring(0, 1).toUpperCase() + substring(1) else this
+    return if (isNotEmpty()) substring(0, 1).uppercase() + substring(1) else this
 }
 
 /**
@@ -97,7 +97,7 @@ public actual fun String.capitalize(): String {
 @Deprecated("Use replaceFirstChar instead.", ReplaceWith("replaceFirstChar { it.lowercase() }"))
 @DeprecatedSinceKotlin(warningSince = "1.5")
 public actual fun String.decapitalize(): String {
-    return if (isNotEmpty()) substring(0, 1).toLowerCase() + substring(1) else this
+    return if (isNotEmpty()) substring(0, 1).lowercase() + substring(1) else this
 }
 
 /**

libraries/stdlib/test/collections/SequenceTest.kt

@@ -122,7 +122,7 @@ public class SequenceTest {
         data.forEach {  }
         assertEquals(0, count, "onEach should be executed only when resulting sequence is iterated")
 
-        val sum = newData.sumBy { it.length }
+        val sum = newData.sumOf { it.length }
         assertEquals(sum, count)
     }
 

libraries/tools/kotlinp/src/org/jetbrains/kotlin/kotlinp/printers.kt

@@ -484,7 +484,7 @@ private fun String.sanitize(quote: Char): String =
                 '\r' -> append("\\r")
                 '\t' -> append("\\t")
                 quote -> append("\\").append(quote)
-                else -> append(if (c.isISOControl()) "\\u%04x".format(c.toInt()) else c)
+                else -> append(if (c.isISOControl()) "\\u%04x".format(c.code) else c)
             }
         }
     }