patterns/includes: Update standard library and patterns to support the new bitfields (#102)

* Add `current_bit_offset()` and `read_bits(...)` to `std::mem`

* Replace deprecated BitfieldOrder enum values with new clearer names

This adds new options named `MostToLeastSignificant` and `LeastToMostSignificant` to replace the old `LeftToRight` and `RightToLeft` names. These names should be much clearer about what they affect and how.

* Throw errors when `std::core::(get|set)_bitfield_order()` are called

* Update all patterns to work with the new bitfield behaviors

patterns/ne.hexpat

@@ -1,7 +1,5 @@
 #include <std/mem.pat>
 
-#pragma bitfield_order right_to_left
-
 struct DOSHeader {
     char signature[2];
     u16 lastPageSize;
@@ -186,7 +184,7 @@ bitfield SegmentTableFlags {
 	containsRelocationInfo : 1;
 	padding : 1;
 	discardPriority : 4;
-} [[right_to_left]];
+};
 
 struct SegmentTable {
 	u16 segmentDataPointer;