Infinite loop with pointer usage in .mmp file

[dfix]

The line Node *p0 = &a0; causes an infinite loop.

typedef struct Node{

	struct Node* next;
	int value;

} Node;

void main () {

	//infinite loop
	Node a0;
	Node *p0 = &a0;
	a0.value = 4;
	assert a0.value == 4;
	assert p0->value == 4;
  
}

java.lang.StackOverflowError

at edu.udel.cis.vsl.tass.front.minimp.ast.type.StructType.equals(StructType.java:84)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.PointerType.equals(PointerType.java:26)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.StructType.equals(StructType.java:87)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.PointerType.equals(PointerType.java:26)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.StructType.equals(StructType.java:87)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.PointerType.equals(PointerType.java:26)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.StructType.equals(StructType.java:87)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.PointerType.equals(PointerType.java:26)
at edu.udel.cis.vsl.tass.front.minimp.ast.type.StructType.equals(StructType.java:87)
at...

[Stephen Siegel]

Fixed defect in AST's Type mechanism. Equals method was not prepared to deal with cycles in type relation, yielding infinite recursion. I broke the recursion at a StructType. Decided two struct types were equal iff their names are equal.