Generate unsigned integers declarations, mostly without implementations

Generate and/or/xor/inv for UByte/UShort using experimental signed counterparts

generators/builtins/common.kt

@@ -36,6 +36,16 @@ enum class PrimitiveType {
     }
 }
 
+enum class UnsignedType {
+    UBYTE,
+    USHORT,
+    UINT,
+    ULONG;
+
+    val capitalized: String get() = name.substring(0, 2) + name.substring(2).toLowerCase()
+    val asSigned: PrimitiveType = PrimitiveType.valueOf(name.substring(1))
+}
+
 enum class ProgressionKind {
     CHAR,
     INT,
@@ -53,3 +63,4 @@ fun areEqualNumbers(v: String) = "$v == other.$v"
 
 fun hashLong(v: String) = "($v xor ($v ushr 32))"
 
+fun convert(v: String, from: UnsignedType, to: UnsignedType) = if (from == to) v else "$v.to${to.capitalized}()"