JACOBIN-610 Alleviate some of anomalies that jacotest case JACOBIN-0433-HexFormat is exposing

[texadactyl]

• Added java/nio/charset/StandardCharsets.<clinit>()V as a trapFunction in otherModules.go.
• Trap HexFormat functions that reference character sets.
• Use uint8 slice type instead of int8 in the G-function for HexFormat.<clinit>. BALOAD and object.ArrayLength cannot handle slices of int8. I suspect other op codes are in the same boat. Also, these are not 1-byte signed integers.
• jdk/internal/util/ArraysSupport.<clinit> needs a call to clinitGeneric.
• Added last 2 static fields: HEX_FORMAT and EMPTY_BYTES.
• Implemented toString() as a G-function.
• Implemented toHexDigits() as G-functions for byte, char, int, long, and short.
• Implemented formatHex([B) as a G-function.

[texadactyl]

At this point in JACOBIN-0433-HexFormat:

HexFormat.ofDelimiter(:) instantiated ok
java.lang.UnsupportedOperationException: INVOKEVIRTUAL: Native method requested: jdk/internal/misc/Unsafe.getLong(Ljava/lang/Object;J)J
  at jdk/internal/misc/Unsafe.getLongUnaligned(Unsafe.java:3523)
  at jdk/internal/util/ArraysSupport.vectorizedMismatch(ArraysSupport.java:130)
  at jdk/internal/util/ArraysSupport.mismatch(ArraysSupport.java:342)
  at java/util/Arrays.equals(Arrays.java:2666)
  at java/util/HexFormat.toString(HexFormat.java:1081)
  at main.main(main.java:7)

Implementing HexFormat.toString() as a G-function will get past this failure.

[platypusguy]

I'm not sure about this edit. We need to be able to handle Java bytes (i.e., int8) at every point in the process where bytes might be accessed. I update BALOAD earlier to work with arrays of int8.

[texadactyl]

@platypusguy
There are probably 2 different issues. It's true that earlier, I got into trouble with both BALOAD and arrays.go object.ArrayLength(). However, bytes are not signed integers; they're unsigned in the context of integers. I think that uint8 is most appropriate in HexFormat.

[texadactyl]

JACOBIN-0433-HexFormat now passes.