Merge #409

409: Fix crashing in assignment operation r=philberty a=teromene

This should fix #407 
The output now looks like:
```
test1.rs:9:17: error: found unexpected token ‘=’ in null denotation
    9 |             a + = 1;
      |                 ^
test1.rs:9:13: error: failed to parse expression for expression without block (pratt-parsed expression is null)
    9 |             a + = 1;
      |             ^
test1.rs:9:13: error: failed to parse statement or expression without block in block expression
test1.rs:9:19: error: failed to parse if body block expression in if expression
    9 |             a + = 1;
      |                   ^
test1.rs:8:9: error: failed to parse expr with block in parsing expr statement
    8 |         if a < 40 {
      |         ^
test1.rs:8:9: error: failed to parse statement or expression without block in block expression
test1.rs:10:11: error: could not parse loop body in (infinite) loop expression
   10 |         } else {
      |           ^
test1.rs:7:5: error: failed to parse expr with block in parsing expr statement
    7 |     loop {
      |     ^
test1.rs:7:5: error: failed to parse statement or expression without block in block expression
test1.rs:14:5: error: unrecognised token ‘return’ for start of item
   14 |     return a;
      |     ^
test1.rs:14:5: error: failed to parse item in crate
```

Co-authored-by: Lyra <teromene@teromene.fr>

0 files changed, 0 insertions, 0 deletions