compiler: hack to make XCreateIC() work on x86-64

basis/compiler/cfg/builder/alien/alien.factor

@@ -108,7 +108,7 @@ M: #alien-invoke emit-node
     [
         {
             [ caller-parameters ]
-            [ alien-invoke-dlsym ##alien-invoke ]
+            [ ##prepare-var-args alien-invoke-dlsym ##alien-invoke ]
             [ emit-stack-frame ]
             [ box-return* ]
         } cleave

basis/compiler/cfg/instructions/instructions.factor

@@ -671,6 +671,8 @@ INSN: ##allot-byte-array
 def: dst/tagged-rep
 literal: size ;
 
+INSN: ##prepare-var-args ;
+
 INSN: ##alien-invoke
 literal: symbols dll ;
 

basis/compiler/codegen/codegen.factor

@@ -294,6 +294,7 @@ CODEGEN: ##prepare-struct-caller %prepare-struct-caller
 CODEGEN: ##box %box
 CODEGEN: ##box-long-long %box-long-long
 CODEGEN: ##allot-byte-array %allot-byte-array
+CODEGEN: ##prepare-var-args %prepare-var-args
 CODEGEN: ##alien-invoke %alien-invoke
 CODEGEN: ##cleanup %cleanup
 CODEGEN: ##alien-indirect %alien-indirect

basis/cpu/architecture/architecture.factor

@@ -589,6 +589,10 @@ HOOK: %restore-context cpu ( temp1 temp2 -- )
 
 HOOK: %save-context cpu ( temp1 temp2 -- )
 
+HOOK: %prepare-var-args cpu ( -- )
+
+M: object %prepare-var-args ;
+
 HOOK: %alien-invoke cpu ( function library -- )
 
 HOOK: %cleanup cpu ( n -- )

basis/cpu/x86/64/unix/unix.factor

@@ -46,3 +46,5 @@ M: x86.64 dummy-int-params? f ;
 M: x86.64 dummy-fp-params? f ;
 
 M: x86.64 temp-reg R8 ;
+
+M: x86.64 %prepare-var-args RAX RAX XOR ;