Fix smart select on last blank line of file (microsoft#32544)

* Fix SmartSelection on last blank line of file

* Add baseline

Author: andrewbranch

src/services/smartSelection.ts

@@ -64,6 +64,13 @@ namespace ts.SmartSelectionRange {
                     parentNode = node;
                     break;
                 }
+
+                // If we made it to the end of the for loop, we’re done.
+                // In practice, I’ve only seen this happen at the very end
+                // of a SourceFile.
+                if (i === children.length - 1) {
+                    break outer;
+                }
             }
         }
 

tests/baselines/reference/smartSelection_lastBlankLine.baseline

@@ -0,0 +1,5 @@
+class C {}
+/**/
+
+
+class C {}↲

tests/cases/fourslash/smartSelection_lastBlankLine.ts

@@ -0,0 +1,5 @@
+/// <reference path="fourslash.ts" />
+////class C {}
+/////**/
+
+verify.baselineSmartSelection();