Allow regular flags to mix with --build

TypeScript Version: 3.0.0-rc, 3.0.0-dev.20180712

Search Terms:

build mode, --build

Code

I have project with the following tsconfig.json:

{
    "compilerOptions": {
        "module": "commonjs",
        "moduleResolution": "node",
        "target": "es2017",
        "lib": ["es2017"],
        "strict": true,
        "sourceMap": true,
        "noEmitOnError": true,
        "types": ["node"]
    },
    "include": [
        "src/**/*.ts"
    ]
}

and compile it with command:

node_modules/.bin/tsc --build tsconfig.json --outDir out --rootDir /home/kostya/proj/foo

Note, that outDir and rootDir options come from command line arguments, because I want to share output directory for another command (clean).

Expected behavior:

outDir and rootDir options will be took from command line.

Actual behavior:

Compiler ignores this options:

node_modules/.bin/tsc --build tsconfig.json --outDir out --rootDir /home/kostya/proj/foo
message TS6096: File '/home/kostya/proj/foo/--outDir' does not exist.

message TS6096: File '/home/kostya/proj/foo/out' does not exist.

message TS6096: File '/home/kostya/proj/foo/--rootDir' does not exist.

Playground Link:

Related Issues: https://github.com/Microsoft/TypeScript/issues/25600

Reproduce the reported tsc --build tsconfig.json --outDir out --rootDir /home/kostya/proj/foo command and inspect the --build argument parsing entry point. Done means regular flags are accepted as compiler options instead of being treated as project paths, while project paths still work.