## Summary:
This lets you write code like:
```
query x {
# @genqlient(typename: "MyString")
someStringField
}
```
and genqlient will do
```
typename MyString string
type x struct {
someStringField MyString
}
```
This was not difficult to implement, though it required introducing a
new identifier type. The main difficulty I had was weird test
failures, that it turns out was due to the tests putting a bunch of
fields on the same line, so that the genqlient directive on the
previous line applied to all of them, accidentally. This became a
problem when `typename` suddenly started being respected for builtin
types! I fixed it by just spreading out the queries a bit.
Fixes#130
## Test plan:
make check
Author: csilvers
Reviewers: dnerdy, StevenACoffman, benjaminjkraft
Required Reviewers:
Approved By: StevenACoffman
Checks: ✅ Test (1.17), ✅ Test (1.16), ✅ Test (1.15), ✅ Test (1.14), ✅ Lint, ✅ Test (1.17), ✅ Test (1.16), ✅ Test (1.15), ✅ Test (1.14), ✅ Lint
Pull Request URL: https://github.com/Khan/genqlient/pull/133
