Existing test files depends on 64bit CPU

[demotomohiro]

In tests directory, there are *.nif and *.c files compared with files generated by nimsem or NIFC when haster runs tests.
Some of these files contains 64bit CPU specific code and when I run tests on 32bit CPU, they doesn't match generated code.

For example, when I compile following code:

var x = 0
var y = 0
discard x == y

nimsem with --bits:32 generates:

 (discard 10
  (eq
   (i +32) ~2 x.0.tesnnc3gc 3 y.0.tesnnc3gc))

but --bits:64 generates:

 (discard 10
  (eq
   (i +64) ~2 x.0.tesnnc3gc 3 y.0.tesnnc3gc)))

NIFC with --bits:32 generates:

#define NIM_INTBITS 32
...
NI x_0_tesnnc3gc = 123;
NI y_0_tesnnc3gc = 123;

--bits:64 generates:

#define NIM_INTBITS 64
...
NI x_0_tesnnc3gc = IL64(123);
NI y_0_tesnnc3gc = IL64(123);

So we probably needs two kinds of *.nif and *.c files for tests like *.32bit.nif and *.32bit.c files for 32bit CPU and *.64bit.c and *.64bit.nif for 64bit CPU.