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/TokenLexer.cpp b/clang/lib/Lex/TokenLexer.cpp
index 724ccb3..184b1b3 100644
--- a/clang/lib/Lex/TokenLexer.cpp
+++ b/clang/lib/Lex/TokenLexer.cpp
@@ -574,7 +574,7 @@
   }
 }
 
-/// \brief Checks if two tokens form wide string literal.
+/// Checks if two tokens form wide string literal.
 static bool isWideStringLiteralFromMacro(const Token &FirstTok,
                                          const Token &SecondTok) {
   return FirstTok.is(tok::identifier) &&
@@ -918,7 +918,7 @@
   PP.HandleMicrosoftCommentPaste(Tok);
 }
 
-/// \brief If \arg loc is a file ID and points inside the current macro
+/// If \arg loc is a file ID and points inside the current macro
 /// definition, returns the appropriate source location pointing at the
 /// macro expansion source location entry, otherwise it returns an invalid
 /// SourceLocation.
@@ -937,7 +937,7 @@
   return MacroExpansionStart.getLocWithOffset(relativeOffset);
 }
 
-/// \brief Finds the tokens that are consecutive (from the same FileID)
+/// Finds the tokens that are consecutive (from the same FileID)
 /// creates a single SLocEntry, and assigns SourceLocations to each token that
 /// point to that SLocEntry. e.g for
 ///   assert(foo == bar);
@@ -1007,7 +1007,7 @@
   }
 }
 
-/// \brief Creates SLocEntries and updates the locations of macro argument
+/// Creates SLocEntries and updates the locations of macro argument
 /// tokens to their new expanded locations.
 ///
 /// \param ArgIdSpellLoc the location of the macro argument id inside the macro