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/utils/TableGen/X86RecognizableInstr.h b/llvm/utils/TableGen/X86RecognizableInstr.h
index 75354c1..a4b0777 100644
--- a/llvm/utils/TableGen/X86RecognizableInstr.h
+++ b/llvm/utils/TableGen/X86RecognizableInstr.h
@@ -272,7 +272,7 @@
   static OperandEncoding writemaskRegisterEncodingFromString(const std::string &s,
                                                              uint8_t OpSize);
 
-  /// \brief Adjust the encoding type for an operand based on the instruction.
+  /// Adjust the encoding type for an operand based on the instruction.
   void adjustOperandEncoding(OperandEncoding &encoding);
 
   /// handleOperand - Converts a single operand from the LLVM table format to