[llvm-c] Make a few function declarations proper prototypes

This avoids warnings when included in a application that
uses -Wstrict-prototypes. 

e.g: AsmPrinters.def:27:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155997 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed