package main

/*
#include <inttypes.h> 
#pragma pack(1)
typedef struct _sss {
uint64_t some; // ok
uint32_t wow; // ok
uint64_t some2; // not found
uint64_t some3; // not found
uint64_t some4; // not found
uint32_t some5; // ok
} Type;
#pragma pack()
*/
import "C"
import (
    "fmt"
)

func main() {
    s := C.Type{}
    s.some = 10; 
    s.wow = 10; 
    s.some2 = 10; 
    s.some5 = 10;
    fmt.Println("Hello, playground")
}

...
type _Ctype_struct__sss struct {
	some	_Ctype_uint64_t
	wow	_Ctype_uint32_t
	_	[24]byte
	some5	_Ctype_uint32_t
}