Remove \brief commands from doxygen comments.

This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
index 93a5ad4..1f2c339 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -124,7 +124,7 @@
   return nullptr;
 }
 
-/// \brief Get filenames for all registered header maps.
+/// Get filenames for all registered header maps.
 void HeaderSearch::getHeaderMapFileNames(
     SmallVectorImpl<std::string> &Names) const {
   for (auto &HM : HeaderMaps)
@@ -404,7 +404,7 @@
   return Result;
 }
 
-/// \brief Given a framework directory, find the top-most framework directory.
+/// Given a framework directory, find the top-most framework directory.
 ///
 /// \param FileMgr The file manager to use for directory lookups.
 /// \param DirName The name of the framework directory.
@@ -600,7 +600,7 @@
 // Header File Location.
 //===----------------------------------------------------------------------===//
 
-/// \brief Return true with a diagnostic if the file that MSVC would have found
+/// Return true with a diagnostic if the file that MSVC would have found
 /// fails to match the one that Clang would have found with MSVC header search
 /// disabled.
 static bool checkMSVCHeaderSearch(DiagnosticsEngine &Diags,
@@ -996,7 +996,7 @@
 // File Info Management.
 //===----------------------------------------------------------------------===//
 
-/// \brief Merge the header file info provided by \p OtherHFI into the current
+/// Merge the header file info provided by \p OtherHFI into the current
 /// header file info (\p HFI)
 static void mergeHeaderFileInfo(HeaderFileInfo &HFI, 
                                 const HeaderFileInfo &OtherHFI) {