bugfix: support carriage return

scalameta/inputs/shared/src/main/scala/scala/meta/internal/inputs/InternalInput.scala

@@ -13,6 +13,8 @@ trait InternalInput {
   private[meta] lazy val tokenCache: mutable.Map[Dialect, Tokens] =
     Compat.newMutableMap[Dialect, Tokens]
 
+  private val newLine = Set('\n', '\r')
+
   // NOTE: It's regrettable that we need to taint the pure abstraction of Input.
   // However, as #334 shows, we just can't redo offset -> line conversions over and over again.
   // This means that we gotta cache, and this instance is really the only place versatile enough.
@@ -21,8 +23,12 @@ trait InternalInput {
     val buf = new mutable.ArrayBuffer[Int]
     buf += 0
     var i = 0
+    var lastIsCR = false
     while (i < chars.length) {
+      // we consider all `\n`, `\r\n` and `\r` as new line
       if (chars(i) == '\n') buf += (i + 1)
+      else if (lastIsCR) buf += i
+      lastIsCR = chars(i) == '\r'
       i += 1
     }
     if (buf.last != chars.length) buf += chars.length // sentinel value used for binary search
@@ -50,7 +56,7 @@ trait InternalInput {
     // NOTE: chars.length requires a really ugly special case.
     // If the file doesn't end with \n, then it's simply last_line:last_col+1.
     // But if the file does end with \n, then it's last_line+1:0.
-    if (offset == chars.length && (0 < chars.length && chars(offset - 1) == '\n')) {
+    if (offset == chars.length && (0 < chars.length && newLine(chars(offset - 1)))) {
       return a.length - 1
     }
     var lo = 0