std.d.parser.Parser.parseAsmUnaExp
public AsmUnaExp parseAsmUnaExp()
Parses an AsmUnaExp 
asmUnaExp:
     asmTypePrefix asmExp
   | Identifier asmExp
   | '+' asmUnaExp
   | '-' asmUnaExp
   | '!' asmUnaExp
   | '~' asmUnaExp
   | asmPrimaryExp
   ;