[clang-format] Don't reflow across comment pragmas.

Summary:
The comment reflower wasn't taking comment pragmas as reflow stoppers. This patch fixes that.

source:
```
// long long long long
// IWYU pragma:
```
format with column limit  = 20 before:
```
// long long long
// long IWYU pragma:
```
format with column limit  = 20 after:
```
// long long long
// long
// IWYU pragma:
```

Reviewers: djasper

Reviewed By: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D29450

llvm-svn: 293898

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 3a100651cab..cd39c54e353 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -1213,7 +1213,7 @@ unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
     BreakableToken::Split SplitBefore(StringRef::npos, 0);
     if (ReflowInProgress) {
       SplitBefore = Token->getSplitBefore(LineIndex, RemainingTokenColumns,
-                                          RemainingSpace);
+                                          RemainingSpace, CommentPragmasRegex);
     }
     ReflowInProgress = SplitBefore.first != StringRef::npos;
     unsigned TailOffset =