Use the same set of whitespace characters for all operations in BreakableToken.

Summary:
Fixes a problem where \t,\v or \f could lead to a crash when placed as
a first character in a line comment. The cause is that rtrim and ltrim handle
these characters, but our code didn't, so some invariants could be broken.

Reviewers: klimek

Reviewed By: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1013

llvm-svn: 184425
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index f20eca1..e4d4c7a 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -893,6 +893,9 @@
                    "    int bbb, // xxxxxxx yyyyyyyyy\n"
                    "    int c, int d, int e) {}",
                    getLLVMStyleWithColumns(40)));
+  EXPECT_EQ("//\t aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+            format("//\t aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+                   getLLVMStyleWithColumns(20)));
 }
 
 TEST_F(FormatTest, PriorityOfCommentBreaking) {