Remove \brief commands from doxygen comments.

This is similar to the LLVM change https://reviews.llvm.org/D46290.

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
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
diff --git a/clang/lib/Sema/JumpDiagnostics.cpp b/clang/lib/Sema/JumpDiagnostics.cpp
index 55582f8..58a7862 100644
--- a/clang/lib/Sema/JumpDiagnostics.cpp
+++ b/clang/lib/Sema/JumpDiagnostics.cpp
@@ -216,7 +216,7 @@
   return ScopePair(0U, 0U);
 }
 
-/// \brief Build scope information for a declaration that is part of a DeclStmt.
+/// Build scope information for a declaration that is part of a DeclStmt.
 void JumpScopeChecker::BuildScopeInformation(Decl *D, unsigned &ParentScope) {
   // If this decl causes a new scope, push and switch to it.
   std::pair<unsigned,unsigned> Diags = GetDiagForGotoScopeDecl(S, D);
@@ -233,7 +233,7 @@
       BuildScopeInformation(Init, ParentScope);
 }
 
-/// \brief Build scope information for a captured block literal variables.
+/// Build scope information for a captured block literal variables.
 void JumpScopeChecker::BuildScopeInformation(VarDecl *D,
                                              const BlockDecl *BDecl,
                                              unsigned &ParentScope) {