Remove \brief commands from doxygen comments.

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

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
diff --git a/llvm/lib/TableGen/TGParser.cpp b/llvm/lib/TableGen/TGParser.cpp
index 8000686..7a0197e 100644
--- a/llvm/lib/TableGen/TGParser.cpp
+++ b/llvm/lib/TableGen/TGParser.cpp
@@ -2387,7 +2387,7 @@
   return false;
 }
 
-/// \brief Apply the current let bindings to \a CurRec.
+/// Apply the current let bindings to \a CurRec.
 /// \returns true on error, false otherwise.
 bool TGParser::ApplyLetStack(Record *CurRec) {
   for (SmallVectorImpl<LetRecord> &LetInfo : LetStack)