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/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index f72fd32..4440600 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -27,7 +27,7 @@
 // C99 6.8: Statements and Blocks.
 //===----------------------------------------------------------------------===//
 
-/// \brief Parse a standalone statement (for instance, as the body of an 'if',
+/// Parse a standalone statement (for instance, as the body of an 'if',
 /// 'while', or 'for').
 StmtResult Parser::ParseStatement(SourceLocation *TrailingElseLoc,
                                   bool AllowOpenMPStandalone) {
@@ -402,7 +402,7 @@
   return Res;
 }
 
-/// \brief Parse an expression statement.
+/// Parse an expression statement.
 StmtResult Parser::ParseExprStatement() {
   // If a case keyword is missing, this is where it should be inserted.
   Token OldToken = Tok;