make inline_gc regparm(3) and cleaned up %call-gc stack alignment

basis/cpu/x86/32/32.factor

@@ -40,6 +40,7 @@ M:: x86.32 %dispatch ( src temp -- )
 ! Registers for fastcall
 M: x86.32 param-reg-1 EAX ;
 M: x86.32 param-reg-2 EDX ;
+M: x86.32 param-reg-3 ECX ;
 
 M: x86.32 pic-tail-reg EBX ;
 

basis/cpu/x86/64/64.factor

@@ -38,7 +38,7 @@ M:: x86.64 %dispatch ( src temp -- )
 
 M: x86.64 param-reg-1 int-regs param-regs first ;
 M: x86.64 param-reg-2 int-regs param-regs second ;
-: param-reg-3 ( -- reg ) int-regs param-regs third ; inline
+M: x86.64 param-reg-3 int-regs param-regs third ;
 
 M: x86.64 pic-tail-reg RBX ;
 

basis/cpu/x86/x86.factor

@@ -55,6 +55,7 @@ HOOK: temp-reg cpu ( -- reg )
 ! Fastcall calling convention
 HOOK: param-reg-1 cpu ( -- reg )
 HOOK: param-reg-2 cpu ( -- reg )
+HOOK: param-reg-3 cpu ( -- reg )
 
 HOOK: pic-tail-reg cpu ( -- reg )
 
@@ -832,8 +833,10 @@ M:: x86 %call-gc ( gc-root-count -- )
     param-reg-1 gc-root-base param@ LEA
     ! Pass number of roots as second parameter
     param-reg-2 gc-root-count MOV
+    ! Pass vm as third argument
+    param-reg-3 0 MOV rc-absolute-cell rt-vm rel-fixup
     ! Call GC
-    "inline_gc" %vm-invoke-3rd-arg ; 
+    "inline_gc" f %alien-invoke ; 
 
 M: x86 %alien-global ( dst symbol library -- )
     [ 0 MOV ] 2dip rc-absolute-cell rel-dlsym ;    

vm/data_gc.cpp

@@ -681,7 +681,7 @@ void factor_vm::inline_gc(cell *gc_roots_base, cell gc_roots_size)
 		gc_locals.pop_back();
 }
 
-VM_ASM_API void inline_gc(cell *gc_roots_base, cell gc_roots_size, factor_vm *myvm)
+VM_ASM_API_OVERFLOW void inline_gc(cell *gc_roots_base, cell gc_roots_size, factor_vm *myvm)
 {
 	ASSERTVM();
 	VM_PTR->inline_gc(gc_roots_base,gc_roots_size);

vm/data_gc.hpp

@@ -20,6 +20,6 @@ PRIMITIVE(gc_stats);
 PRIMITIVE(clear_gc_stats);
 PRIMITIVE(become);
 struct factor_vm;
-VM_ASM_API void inline_gc(cell *gc_roots_base, cell gc_roots_size, factor_vm *myvm);
+VM_ASM_API_OVERFLOW void inline_gc(cell *gc_roots_base, cell gc_roots_size, factor_vm *myvm);
 
 }