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/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
index 2b3d4ba..bccf423 100644
--- a/clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -733,7 +733,7 @@
   }
 }
 
-/// \brief Consume tokens and store them in the passed token container until
+/// Consume tokens and store them in the passed token container until
 /// we've passed the try keyword and constructor initializers and have consumed
 /// the opening brace of the function body. The opening brace will be consumed
 /// if and only if there was no error.
@@ -937,7 +937,7 @@
   }
 }
 
-/// \brief Consume and store tokens from the '?' to the ':' in a conditional
+/// Consume and store tokens from the '?' to the ':' in a conditional
 /// expression.
 bool Parser::ConsumeAndStoreConditional(CachedTokens &Toks) {
   // Consume '?'.
@@ -962,7 +962,7 @@
   return true;
 }
 
-/// \brief A tentative parsing action that can also revert token annotations.
+/// A tentative parsing action that can also revert token annotations.
 class Parser::UnannotatedTentativeParsingAction : public TentativeParsingAction {
 public:
   explicit UnannotatedTentativeParsingAction(Parser &Self,