[nnc] Make the pretty printer prettier (#57874)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57874
Before:
```
{
for (int v = 0; v < 100; v++) {
aten_sin[v] = sin(x_1[v]);
}
{
sum = float(0);
for (int v_1 = 0; v_1 < 100; v_1++) {
sum = ReduceOp((sum) + float(aten_sin[v_1]), reduce_args={});
}
} for (int v_2 = 0; v_2 < 100; v_2++) {
aten_cos[v_2] = cos(x_1[v_2]);
}
for (int v_3 = 0; v_3 < 100; v_3++) {
aten_mul[v_3] = (_tensor_constant0[v_3]) * (aten_cos[v_3]);
}
}
```
After:
```
{
for (int v = 0; v < 100; v++) {
aten_sin[v] = sin(x_1[v]);
}
{
sum = float(0);
for (int v_1 = 0; v_1 < 100; v_1++) {
sum = ReduceOp((sum) + float(aten_sin[v_1]), reduce_args={});
}
}
for (int v_2 = 0; v_2 < 100; v_2++) {
aten_cos[v_2] = cos(x_1[v_2]);
}
for (int v_3 = 0; v_3 < 100; v_3++) {
aten_mul[v_3] = (_tensor_constant0[v_3]) * (aten_cos[v_3]);
}
}
```
Test Plan: Imported from OSS
Reviewed By: navahgar, malfet
Differential Revision: D28455842
Pulled By: bertmaher
fbshipit-source-id: 6d5ca9be12afd66a9ba32c129a3f4d618247cd35
