feat: implement proper IR with value handles with dynamic and transferable types

TODO.md

@@ -17,4 +17,12 @@
 - Live intervals
 - Linear scan allocator with ~6 fake regs
 - Spill to stack slots
-- Add “CALL clobbers regs” rule
+- Add “CALL clobbers regs” rule
+
+
+function's reserved registers:
+  EAX, ECX, EDX
+
+return registers:
+  int => EAX
+  float => ST0