Enhance robustness of '[ ]' operator for array access.

[HPCguy]

Creating an issue for this so it can be tracked.

Using an array operator '[ ]' is currently supported for use with (certain) pointer variables in array expressions, but not always. The goal of this ticket is to be able to use the array operator '[ ]' in expressions, working as expected under every possible circumstance. Note that having '[ ]' work for declarations also needs to be improved, and is submitted as a separate issue.

[HPCguy]

I am opening a branch to work on this.

For example, compiling the following:

int main()
{
struct point {
int x, y;
} *p;
int i;

p = (struct point *) malloc(10*sizeof(struct point));

for (i = 0; i < 10; ++i) {
p[i].x = 0;
}

return 0;
}

results in the error:

$ ./amacc -o arr arr.c
16: compiler error gen=-1228300496

[HPCguy]

Closed by #88