ARM: print COFF function header for Windows on ARM

Emit the COFF header when printing out the function.  This is important as the
header contains two important pieces of information: the storage class for the
symbol and the symbol type information.  This bit of information is required for
the linker to correctly identify the type of symbol that it is dealing with.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207613 91177308-0d34-0410-b5e6-96231b3b80d8