C++ identifiers generated with `-upper-acronyms` have lowercase word-initial acronyms

An example is online at the link below:
https://app.quicktype.io?share=rzzbSvHzvOuzJXhI64yk

For future reference, the following is the situation:

## Schema
```json
{
"$schema": "http://json-schema.org/draft-06/schema#",
"description": "An array of SCUBA waypoints",
"type": "array",
"items": {
"title": "SCUBAWaypoint",
"type": "object",
"properties": {
"location": {
"title": "Point",
"type": "object",
"properties": {
"latitude": {
"type": "number"
},
"longitude": {
"type": "number"
}
}
},
"depth": {
"type": "number"
},
"maneuver": {
"title": "SCUBAManeuver",
"type": "string",
"enum": [
"ASCENT",
"DESCENT",
"LEVEL"
]
}
}
}
}
```

## Quicktype CLI Command
```bash
quicktype --src-lang schema --lang c++ --namespace SCUBAJSON \
--source-style multi-source --include-location global-include \
--type-style pascal-case-upper-acronyms --member-style camel-case-upper-acronyms \
--out ./scuba.hpp --src scuba.jsonschema
```

## Desired Output
```cpp
enum class SCUBAManeuver { ... }
...
struct SCUBAWaypoint { ... }
// etc...
```

## Actual Output
```cpp
enum class ScubaManeuver { ... }
...
struct ScubaWaypoint { ... }
// etc...
```