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/Frontend/VerifyDiagnosticConsumer.cpp b/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
index 129a233..21933f4 100644
--- a/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/clang/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -80,7 +80,7 @@
   VerifyFileTracker(VerifyDiagnosticConsumer &Verify, SourceManager &SM)
       : Verify(Verify), SM(SM) {}
 
-  /// \brief Hook into the preprocessor and update the list of parsed
+  /// Hook into the preprocessor and update the list of parsed
   /// files when the preprocessor indicates a new file is entered.
   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
                    SrcMgr::CharacteristicKind FileType,
@@ -656,7 +656,7 @@
 }
 
 #ifndef NDEBUG
-/// \brief Lex the specified source file to determine whether it contains
+/// Lex the specified source file to determine whether it contains
 /// any expected-* directives.  As a Lexer is used rather than a full-blown
 /// Preprocessor, directives inside skipped #if blocks will still be found.
 ///
@@ -694,7 +694,7 @@
 }
 #endif // !NDEBUG
 
-/// \brief Takes a list of diagnostics that have been generated but not matched
+/// Takes a list of diagnostics that have been generated but not matched
 /// by an expected-* directive and produces a diagnostic to the user from this.
 static unsigned PrintUnexpected(DiagnosticsEngine &Diags, SourceManager *SourceMgr,
                                 const_diag_iterator diag_begin,
@@ -722,7 +722,7 @@
   return std::distance(diag_begin, diag_end);
 }
 
-/// \brief Takes a list of diagnostics that were expected to have been generated
+/// Takes a list of diagnostics that were expected to have been generated
 /// but were not and produces a diagnostic to the user from this.
 static unsigned PrintExpected(DiagnosticsEngine &Diags,
                               SourceManager &SourceMgr,
@@ -753,7 +753,7 @@
   return DL.size();
 }
 
-/// \brief Determine whether two source locations come from the same file.
+/// Determine whether two source locations come from the same file.
 static bool IsFromSameFile(SourceManager &SM, SourceLocation DirectiveLoc,
                            SourceLocation DiagnosticLoc) {
   while (DiagnosticLoc.isMacroID())