Fixing sphinx build due to diagnostic:

/opt/llvm/build.attributes.src/tools/clang/docs/CommandGuide/clang.rst:338: WARNING: unknown option: -flto=full

llvm-svn: 282148
diff --git a/clang/docs/CommandGuide/clang.rst b/clang/docs/CommandGuide/clang.rst
index f600315..1056415 100644
--- a/clang/docs/CommandGuide/clang.rst
+++ b/clang/docs/CommandGuide/clang.rst
@@ -328,7 +328,7 @@
   model can be overridden with the tls_model attribute. The compiler will try
   to choose a more efficient model if possible.
 
-.. option:: -flto[=full,thin], -emit-llvm
+.. option:: -flto, -flto=full, -flto=thin, -emit-llvm
 
   Generate output files in LLVM formats, suitable for link time optimization.
   When used with :option:`-S` this generates LLVM intermediate language