some errors in the specification (january 30 version)

[Eric Bruneton]

FYI, I updated the type annotation implementation in the ASM branch 
ASM_5_FUTURE, to match the latest version of the JSR. I hope it is 
correct, but I have no reference implementation against which to test it 
(is there one)?

By doing this, I noticed two small bugs in the specification:
- the first sentence in 3.3.10 references 
invocation_type_argument_target and method_reference_type_argument, 
which are not defined.
- in 3.4, in the type_path_entry struct definition, the 
type_argument_index comment is inconsistent with the sentence just below 
"When type_path_kind is 0, 1, or 2, then type_argument_index must be 0" 
(0 is valid for a type_path_kind 3, and designates the 1st type arg).

Finally I'm wondering, in 3.3.10, how the value of type_argument_index 
is defined for a castinstruction.

Eric