Fix a typo in comment.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169078 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/SourceLocation.h

@@ -218,7 +218,7 @@ class SourceRange {
 /// \brief Represents a character-granular source range.
 ///
 /// The underlying SourceRange can either specify the starting/ending character
-/// of the range, or it can specify the start or the range and the start of the
+/// of the range, or it can specify the start of the range and the start of the
 /// last token of the range (a "token range").  In the token range case, the
 /// size of the last token must be measured to determine the actual end of the
 /// range.