Migrate compiler, idea and others to new case conversion api

core/compiler.common/src/org/jetbrains/kotlin/name/NameUtils.kt

@@ -39,10 +39,10 @@ object NameUtils {
 
     @JvmStatic
     private fun capitalizeAsJavaClassName(str: String): String =
-            // NB use Locale.ENGLISH so that build is locale-independent.
+            // NB `uppercase` uses Locale.ROOT and is locale-independent.
             // See Javadoc on java.lang.String.toUpperCase() for more details.
             if (Character.isJavaIdentifierStart(str[0]))
-                str.substring(0, 1).toUpperCase(Locale.ENGLISH) + str.substring(1)
+                str.substring(0, 1).uppercase() + str.substring(1)
             else
                 "_$str"
 

core/descriptors/src/org/jetbrains/kotlin/builtins/functions/FunctionInvokeDescriptor.kt

@@ -138,7 +138,7 @@ class FunctionInvokeDescriptor private constructor(
                 "E" -> "receiver"
                 else -> {
                     // Type parameter "P1" -> value parameter "p1", "P2" -> "p2", etc.
-                    typeParameterName.toLowerCase()
+                    typeParameterName.lowercase()
                 }
             }
 

core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRendererOptionsImpl.kt

@@ -48,7 +48,7 @@ internal class DescriptorRendererOptionsImpl : DescriptorRendererOptions {
             assert(!field.name.startsWith("is")) { "Fields named is* are not supported here yet" }
             val value = property.getValue(
                     this,
-                    PropertyReference1Impl(DescriptorRendererOptionsImpl::class, field.name, "get" + field.name.capitalize())
+                    PropertyReference1Impl(DescriptorRendererOptionsImpl::class, field.name, "get" + field.name.replaceFirstChar(Char::uppercaseChar))
             )
             field.set(copy, copy.property(value))
         }

core/util.runtime/src/org/jetbrains/kotlin/utils/capitalizeDecapitalize.kt

@@ -28,7 +28,7 @@ fun String.decapitalizeSmartForCompiler(asciiOnly: Boolean = false): String {
     if (isEmpty() || !isUpperCaseCharAt(0, asciiOnly)) return this
 
     if (length == 1 || !isUpperCaseCharAt(1, asciiOnly)) {
-        return if (asciiOnly) decapitalizeAsciiOnly() else decapitalize()
+        return if (asciiOnly) decapitalizeAsciiOnly() else replaceFirstChar(Char::lowercaseChar)
     }
 
     val secondWordStart = (indices.firstOrNull { !isUpperCaseCharAt(it, asciiOnly) } ?: return toLowerCase(this, asciiOnly)) - 1
@@ -98,18 +98,18 @@ private fun String.isLowerCaseCharAt(index: Int, asciiOnly: Boolean): Boolean {
 }
 
 private fun toLowerCase(string: String, asciiOnly: Boolean): String {
-    return if (asciiOnly) string.toLowerCaseAsciiOnly() else string.toLowerCase()
+    return if (asciiOnly) string.toLowerCaseAsciiOnly() else string.lowercase()
 }
 
 private fun toUpperCase(string: String, asciiOnly: Boolean): String {
-    return if (asciiOnly) string.toUpperCaseAsciiOnly() else string.toUpperCase()
+    return if (asciiOnly) string.toUpperCaseAsciiOnly() else string.uppercase()
 }
 
 fun String.capitalizeAsciiOnly(): String {
     if (isEmpty()) return this
     val c = this[0]
     return if (c in 'a'..'z')
-        c.toUpperCase() + substring(1)
+        c.uppercaseChar() + substring(1)
     else
         this
 }
@@ -118,7 +118,7 @@ fun String.decapitalizeAsciiOnly(): String {
     if (isEmpty()) return this
     val c = this[0]
     return if (c in 'A'..'Z')
-        c.toLowerCase() + substring(1)
+        c.lowercaseChar() + substring(1)
     else
         this
 }
@@ -126,7 +126,7 @@ fun String.decapitalizeAsciiOnly(): String {
 fun String.toLowerCaseAsciiOnly(): String {
     val builder = StringBuilder(length)
     for (c in this) {
-        builder.append(if (c in 'A'..'Z') c.toLowerCase() else c)
+        builder.append(if (c in 'A'..'Z') c.lowercaseChar() else c)
     }
     return builder.toString()
 }
@@ -134,7 +134,7 @@ fun String.toLowerCaseAsciiOnly(): String {
 fun String.toUpperCaseAsciiOnly(): String {
     val builder = StringBuilder(length)
     for (c in this) {
-        builder.append(if (c in 'a'..'z') c.toUpperCase() else c)
+        builder.append(if (c in 'a'..'z') c.uppercaseChar() else c)
     }
     return builder.toString()
 }