VM replaces declared type with alias

[jcosborn]

In the below code, the type of x is set to Foo even though it was declared int and Foo is not in scope.
This causes a compiler crash later when x is used since Foo is a generic and wasn't instantiated.

Example

block:
  type
    Foo[n: static int] = int

block:
  static:
    let x = int 1
    echo x.type   # Foo                                                                   

block:
  static:
    let x = int 1
    let y = x + 1
    # Error: unhandled exception: value out of range: -8 notin 0 .. 65535 [RangeDefect]   
    echo y

Current Output

Foo
fatal.nim(53)            sysFatal
Error: unhandled exception: value out of range: -8 notin 0 .. 65535 [RangeDefect]

Expected Output

int
2

Possible Solution

Additional Information

This happens on devel, 1.6 and 1.4.

This is related to #15356.