Minor comment typo fix

'se' -> 'so'

Author: Undo1

lib/AST/Pattern.cpp

@@ -744,7 +744,7 @@ SourceLoc TuplePattern::getAnyEllipsisLoc() const {
 
 SourceRange TypedPattern::getSourceRange() const {
   if (isImplicit()) {
-    // If a TypedPattern is implicit, then its type is definitely implicit, se
+    // If a TypedPattern is implicit, then its type is definitely implicit, so
     // we should ignore its location.  On the other hand, the sub-pattern can
     // be explicit or implicit.
     return SubPattern->getSourceRange();