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/BypassSlowDivision.cpp b/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
index 09ef84a..08ccfbc 100644
--- a/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
+++ b/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
@@ -173,7 +173,7 @@
   return isDivisionOp() ? Value.Quotient : Value.Remainder;
 }
 
-/// \brief Check if a value looks like a hash.
+/// Check if a value looks like a hash.
 ///
 /// The routine is expected to detect values computed using the most common hash
 /// algorithms. Typically, hash computations end with one of the following