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/Transforms/Utils/LowerSwitch.cpp b/llvm/lib/Transforms/Utils/LowerSwitch.cpp
index f18bd25..efdc04a 100644
--- a/llvm/lib/Transforms/Utils/LowerSwitch.cpp
+++ b/llvm/lib/Transforms/Utils/LowerSwitch.cpp
@@ -172,7 +172,7 @@
   return O << "]";
 }
 
-/// \brief Update the first occurrence of the "switch statement" BB in the PHI
+/// Update the first occurrence of the "switch statement" BB in the PHI
 /// node with the "new" BB. The other occurrences will:
 ///
 /// 1) Be updated by subsequent calls to this function.  Switch statements may