remove parameters from x86 function defs

book.tex

@@ -7694,7 +7694,7 @@ x86_3 &::= & (\key{program} \;\itm{info} \;\Def\ldots)
   \Instr &::=& \ldots \mid \INDCALLQ{\itm{label}}{\itm{int}}
     \mid \TAILJMP{\Arg}{\itm{int}}\\
     &\mid& \BININSTR{\code{'leaq}}{\Arg}{\REG{\Reg}}\\
-  \Def &::= & \DEF{\itm{label}}{([\Var\key{:}\Type]\ldots)}{\Type}{\itm{info}}{((\itm{label}\,\key{.}\,\Block)\ldots)} \\
+  \Def &::= & \DEF{\itm{label}}{\code{'()}}{\Type}{\itm{info}}{((\itm{label}\,\key{.}\,\Block)\ldots)} \\
 x86_3 &::= & \PROGRAMDEFS{\itm{info}}{(\Def\ldots)}
 \end{array}
 \]