Fix -dA flag, it is not a preprocessor flag.

-dA was in the d_group, which is a preprocessor state dumping group.
However -dA is a debug flag to cause a verbose asm.  It was already
implemented to do the same thing as -fverbose-asm, so make it just be an
alias.

llvm-svn: 369926
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
index aa53782..c26a6e5 100644
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -1147,8 +1147,6 @@
 .. option:: -d<arg>
 .. program:: clang
 
-.. option:: -dA
-
 .. option:: -dD
 
 Print macro definitions in -E mode in addition to normal output
@@ -2012,7 +2010,7 @@
 
 Enable the loop vectorization passes
 
-.. option:: -fverbose-asm, -fno-verbose-asm
+.. option:: -fverbose-asm, -fno-verbose-asm, -dA
 
 .. option:: -fvisibility-inlines-hidden