Compiler bug when Hash block always raises

[carlhoerberg]

This is stupid code of course, but still, Crystal raises an error instead of pointing out the error.

crystal eval 'Hash(String, String).new { |h, k| h[k] = raise "" }'
Cast from Nil to Crystal::ProcInstanceType failed, at /tmp/crystal/src/compiler/crystal/semantic/bindings.cr:535:7:535 (TypeCastError)
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '??'
  from crystal in '__crystal_main'
  from crystal in 'main'
  from /lib64/libc.so.6 in '??'
  from /lib64/libc.so.6 in '__libc_start_main'
  from crystal in '_start'
  from ???
Error: you've found a bug in the Crystal compiler. Please open an issue, including source code that will allow us to reproduce the bug: https://github.com/crystal-lang/crystal/issues

 ✗ crystal -v
Crystal 1.9.2 [1908c81] (2023-07-19)

LLVM: 16.0.6
Default target: x86_64-redhat-linux-gnu

[HertzDevil]

Reduced:

def foo(block)
end

def bar(&block : -> String)
  foo block
end

bar { asdf(while true; end) }