Generic use of member constraint solved to record field causes crash

[drvink]

The following program typechecks, but crashes.

#light "off"
#nowarn "62";;

open System

type hober<'a> = { foo : 'a }
type gromus<'a> = { foo : 'a }
type hoobler<'a>(arg : 'a) = class
  member __.foo = arg
end

let inline
  print_foo_memb<'a, 'b when
    ^a :         (member foo : 'b)
                >
    x =
  printfn "%A" (^a : (member foo : 'b) x)

[<EntryPoint>]
let main _ =
  let a : hober<_> = { foo=1 } in
  let b : gromus<_> = { foo="horp" } in
  let c = hoobler("durr") in
  // these are ok
  print_foo_memb<_, int> a;
  print_foo_memb<_, string> b;
  print_foo_memb<_, string> c;
  // these will cause a crash!
  print_foo_memb a;
  print_foo_memb b;
  // but it seems to only happen when the (unannotated) function is applied to
  // a record--classes are ok
  print_foo_memb c;
  0

On .NET:

Managed Debugging Assistant 'FatalExecutionEngineError' has detected a problem in 'c:\users\msjp_000\documents\visual studio 2013\Projects\crashy\crashy\bin\Debug\crashy.exe'.

Additional information: The runtime has encountered a fatal error. The address of the error was at 0x72110237, on thread 0xd68. The error code is 0xc0000005. This error may be a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common sources of this bug include user marshaling errors for COM-interop or PInvoke, which may corrupt the stack.

On Mono:

Unhandled Exception:
System.InvalidProgramException: Invalid IL code in Horp:main (string[]): IL_0082: callvirt  0x0a00000f

[ERROR] FATAL UNHANDLED EXCEPTION: System.InvalidProgramException: Invalid IL code in Horp:main (string[]): IL_0082: callvirt  0x0a00000f

This is with both fsc 3.1 and fsharpc 3.1.

[latkin]

Repros for me in 4.0. The "bad" lines result in nonverifiable generated code with object type parameter in calls, instead of proper int or string.

[dsyme]

Minified repro:

type hober<'a> = { foo : 'a }
let inline f x = box (^a : (member foo : 'b) x)
let v = f { foo=1 }