Align JS String.equals/compareTo(ignoreCase) behavior with JVM #KT-48999

kotlin-native/runtime/src/main/kotlin/kotlin/text/Strings.kt

@@ -35,6 +35,9 @@ internal actual external fun String.nativeLastIndexOf(str: String, fromIndex: In
 /**
  * Returns `true` if this string is equal to [other], optionally ignoring character case.
  *
+ * Two strings are considered to be equal if they have the same length and the same character at the same index.
+ * If [ignoreCase] is true, the result of `Char.uppercaseChar().lowercaseChar()` on each character is compared.
+ *
  * @param ignoreCase `true` to ignore character case when comparing strings. By default `false`.
  */
 @Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
@@ -475,6 +478,11 @@ internal fun compareToIgnoreCase(thiz: String, other: String): Int {
         1
 }
 
+/**
+ * Compares two strings lexicographically, optionally ignoring case differences.
+ *
+ * If [ignoreCase] is true, the result of `Char.uppercaseChar().lowercaseChar()` on each character is compared.
+ */
 @Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
 public actual fun String.compareTo(other: String, ignoreCase: Boolean = false): Int {
     return if (!ignoreCase) this.compareTo(other)