avoid sulong issue with intrinsics returning "void"

Author: lukasstadler

graalpython/com.oracle.graal.python.cext/src/capi.c

@@ -718,6 +718,12 @@ PyAPI_FUNC(void*) truffle_calloc(size_t size) {
 	return calloc(1, size);
 }
 
+// avoid problems with calling "void" intrinsics via interop
+PyAPI_FUNC(int) truffle_free(void* ptr) {
+	free(ptr);
+	return 1;
+}
+
 PyAPI_FUNC(void) register_native_slots(PyTypeObject* managed_class, PyGetSetDef* getsets, PyMemberDef* members) {
     if (getsets || members) {
         GraalPyTruffle_Set_Native_Slots(managed_class, getsets, members);

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/capi/NativeCAPISymbol.java

@@ -169,7 +169,7 @@ public enum NativeCAPISymbol implements NativeCExtSymbol {
     // ctypes
     FUN_STRLEN("strlen", SIZE_T, Pointer),
     FUN_MEMCPY("memcpy", Pointer, Pointer, Pointer, SIZE_T),
-    FUN_FREE("free", ArgDescriptor.Void, Pointer),
+    FUN_FREE("truffle_free", Int, Pointer),
     FUN_MEMMOVE("memmove", Pointer, Pointer, Pointer, SIZE_T),
     FUN_MEMSET("memset", Pointer, Pointer, Int, SIZE_T),
     FUN_CALLOC("truffle_calloc", Pointer, SIZE_T),