Show correct PC counter in scan

src/mos6502.dis.c

@@ -343,7 +343,13 @@ mos6502_dis_opcode(mos6502 *cpu, FILE *stream, int address)
 void
 mos6502_dis_scan(mos6502 *cpu, FILE *stream, int pos, int end)
 {
+    vm_16bit pc;
+
+    pc = cpu->PC;
     while (pos < end) {
+        cpu->PC = pos;
         pos += mos6502_dis_opcode(cpu, stream, pos);
     }
+
+    cpu->PC = pc;
 }

src/vm_debug.c

@@ -439,7 +439,7 @@ DEBUG_CMD(dblock)
     }
 
     mos6502 *cpu = (mos6502 *)vm_di_get(VM_CPU);
-    FILE *stream = (FILE *)vm_di_get(VM_OUTPUT);
+    FILE *stream = log_stream();
 
     mos6502_dis_scan(cpu, stream, args->addr1, args->addr2);
 }

tests/mos6502.dis.c

@@ -231,6 +231,6 @@ Test(mos6502_dis, scan)
     // runtime operation) when you don't want it to, but as a standalone
     // disassembler, it feels less useful when PC isn't emulated.
     assert_buf("0000:29 38                     AND   #$38\n"
-               "0000:88                        DEY   \n"
-               "0000:6C 34 12                  JMP   ($1234)\n");
+               "0002:88                        DEY   \n"
+               "0003:6C 34 12                  JMP   ($1234)\n");
 }

tests/vm_debug.c

@@ -28,6 +28,7 @@ setup()
     }
 
     vm_di_set(VM_OUTPUT, stream);
+    log_open(stream);
 
     // Writing to stream will now write to buf
     setvbuf(stream, buf, _IOFBF, BUFSIZ);