Fix hashmap collisions sometimes hanging deletion

test/asm/sym-collision.asm

@@ -0,0 +1,34 @@
+; Hashmap collisions are pretty poorly-tested code path...
+; At some point, `PURGE` would malfunction with them
+
+SECTION "Collision course", OAM[$FE00]
+
+; All the following symbols collide!
+aqfj: ds 1 ; Give them different addresses
+cxje: ds 1
+dgsd: ds 1
+dork: ds 1
+lxok: ds 1
+psgp: ds 1
+sfly: ds 1
+syyq: ds 1
+ussg: ds 1
+xlmm: ds 1
+xtzp: ds 1
+zxfr: ds 1
+
+	; Completely by accident, but cool
+	PURGE dork
+
+	PRINTT "aqfj: {aqfj}\n"
+	PRINTT "cxje: {cxje}\n"
+	PRINTT "dgsd: {dgsd}\n"
+	PRINTT "dork: {dork}\n"
+	PRINTT "lxok: {lxok}\n"
+	PRINTT "psgp: {psgp}\n"
+	PRINTT "sfly: {sfly}\n"
+	PRINTT "syyq: {syyq}\n"
+	PRINTT "ussg: {ussg}\n"
+	PRINTT "xlmm: {xlmm}\n"
+	PRINTT "xtzp: {xtzp}\n"
+	PRINTT "zxfr: {zxfr}\n"