Fix an inconsistency in the x86 backend that led it to reject "calll foo" on

x86-32: 32-bit calls were named "call" not "calll".  64-bit calls were correctly
named "callq", so this only impacted x86-32.

This fixes rdar://8456370 - llvm-mc rejects 'calll'

This also exposes that mingw/64 is generating a 32-bit call instead of a 64-bit call,
I will file a bugzilla.

llvm-svn: 114534