Better "See also" targeting

[parno]

Currently, Vale/F* reports most verification errors in terms of the original Vale source code. However, the treatment of the "See also" reporting is current rather odd. In the example below, the "Also see" parenthetical reported with the error message points to line 0 column 0. However, the "see also" for the corresponding warning contains useful line and column information. Unfortunately, that information points to the generated F* file X64.AESGCM.fst instead of the precondition on the original Vale procedure. Fixing either one or both of these limitations would help improve the Vale debug cycle.

(0,0-0,0): (Warning 252) ***** PRECONDITION NOT MET AT line 3168 column 16 of file ./code/thirdPartyPorts/OpenSSL/aes/X64.AESGCM.vaf ***** (see also obj/code/thirdPartyPorts/OpenSSL/aes/X64.AESGCM.fst(310,28-310,68))
obj/code/thirdPartyPorts/OpenSSL/aes/X64.AESGCM.fst(886,2-909,16): (Error 19) ***** PRECONDITION NOT MET AT line 3168 column 16 of file ./code/thirdPartyPorts/OpenSSL/aes/X64.AESGCM.vaf ***** (Also see: (0,0-0,0))