Add -mfpu=neon-vfpv4

This enables user to architecturally specify ARMv7A + VFPv4 + NEON.

Change-Id: I779b01fef5c47e5e4ac702ae24ed2f76a0e4c63f

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@222932 91177308-0d34-0410-b5e6-96231b3b80d8
Add additional arguments for -mfpu options

Add neon-vfpv3 to allow specifying both at the same time. This is not an
option that GCC supports, but follows the same track and should be
non-controversial.

Change-Id: Id9ec157c835937d7d11ad0f49dbe5171fac17658

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@222933 91177308-0d34-0410-b5e6-96231b3b80d8