Implement BITWIDTH and TZCOUNT functions (#1450)

test/asm/bit-functions.asm

@@ -0,0 +1,11 @@
+assert BITWIDTH(0) == 0
+assert BITWIDTH(42) == 6
+assert BITWIDTH(-1) == 32
+assert BITWIDTH($80000000) == 32
+
+assert TZCOUNT(0) == 32
+assert TZCOUNT(42) == 1
+assert TZCOUNT(-1) == 0
+assert TZCOUNT($80000000) == 31
+
+assert TZCOUNT(1.0) == 16

test/link/operators.asm

@@ -27,3 +27,6 @@ db @ <= 7
 dw @ << 1
 dw @ >> 1
 dw @ >>> 1
+
+db BITWIDTH(@)
+db TZCOUNT(@)