feat(v4): the system's UM*, UM/MOD, D+, DNEGATE, Q.* and Q./ call the ROM

MACHINE.md 2.2.  Each is its entry's address, push and ;.  Every node the
tests make carries the host ROM (host_load, Hera's births, the depth and
mesh tests' own nodes), and a division by zero inside the ROM returns to
the prompt (hosted-check).  test_host_quit's fetch outside memory moves
past the ROM's range: 16384 is the ROM's first word now the tests' system
has its ROM, as the product's always had.  dict_hash 0xfec8c47cfc6f437f.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

v4/tools/mkmap.c

@@ -31,6 +31,9 @@ static int system_map(void)
 #define SYS_CONSTANT(name, value) constant(name, (long)(v4_cell)(value));
     HOST_CONSTANTS(SYS_CONSTANT)
 #undef SYS_CONSTANT
+#define SYS_ROM_ENTRY(i, routine, forth, effect) constant("ROM-" forth, (long)(V4_ROM_BASE + (v4_cell)(i)));
+    V4_ROM_MATH_ENTRIES(SYS_ROM_ENTRY)
+#undef SYS_ROM_ENTRY
     constant("DICT-W", (long)DICT_W);
     constant("(IMG)", (long)ROM_IMG);
     return 0;