ARM: add some TODOs for future accuracy research

src/nba/src/arm/arm7tdmi.hpp

@@ -16,6 +16,13 @@
 #include "bus/bus.hpp"
 #include "arm/state.hpp"
 
+/**
+ * Some TODOs:
+ * - test LDR, STR, LDM and STM behavior when writing back the address to r15
+ * - test which bits of CPSR and SPSR are actually writable
+ * - more accurately model when CPSR.mask_irq and the IRQ line are sampled
+ */
+
 namespace nba::core::arm {
 
 struct ARM7TDMI {