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/Target/WebAssembly/WebAssembly.td b/llvm/lib/Target/WebAssembly/WebAssembly.td
index 33a4cd3..ad1549f 100644
--- a/llvm/lib/Target/WebAssembly/WebAssembly.td
+++ b/llvm/lib/Target/WebAssembly/WebAssembly.td
@@ -8,7 +8,7 @@
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// \brief This is a target description file for the WebAssembly architecture,
+/// This is a target description file for the WebAssembly architecture,
 /// which is also known as "wasm".
 ///
 //===----------------------------------------------------------------------===//