Remove syntax hint for casting
Do sign-extension based on opcode field
Add tests for sign-extension
Fix sext64 test reference
Opcode encoding for inv64
Add vendor specific tests
Replace the use of inv64 with /m=!64

Change also includes some more tests
New operand types in optable.xml

Introduce operand types Fv (far pointer in memory), Av (pointer
operand). Also make pinsrw default to 64bit operand size.
Clean up operand casting for intel syntax