Print some Warnings

[PhilippvK]

Prints warnings if unsupported (or undefined) behavior is detected:

• Implicit truncations (e.g. unsigned<16> my_u16_val = my_u32_val; vs. unsigned<16> my_u16_val = my_u32_val[15:0];)
• Shifting values out of range (number of bits in LHS) (e.g. my_u32_val << 33 or even 1'b1 << 2).

TODOs

• Expose via CLI (e.g. -Wall, -Wimplicit-trunc, -Wno-implicit-trunc,...)
• Print line in code where warning was emitted
• Move warnings from etiss writer to coredsl2 parser
• Drop warnings code from etiss writer
• Add more warnings:
  • implicit-extend
  • bit-op-missmatch
  • sign-compare
  • shift-signed
  • unused-value -> Move to extra issue

[PhilippvK]

Moving to the parser has to be delayed after the type inference pass was upstreamed.

[jokap11]

TODO: Remember for later to merge with #72
Needs update for Ranged Index Access.
self.right is completely missing in PASS