[8.x] Throw exception when unable to create LockableFile

[JVMartin]

We run into this cryptic error in our production Laravel servers:

This is because LockableFile incorrectly presumes that the result of fopen (which is stored in $this->handle) is always a file pointer resource, when in fact it can be the boolean value false when the file failed to create properly - relevant docs. When the file fails to create, $this->handle silently gets set to false here:

framework/src/Illuminate/Filesystem/LockableFile.php

Lines 65 to 68 in 72ea328

	protected function createResource($path, $mode)
	{
	$this->handle = @fopen($path, $mode);
	}

...such that subsequent references to $this->handle will fail with the above cryptic message, when in fact the real error happened much earlier when the file was supposed to be created.

If, instead, we throw an exception when fopen fails, the developer will see a helpful error showing the actual path of the file which failed to create, so that we can action upon that, whether it be updating the group permissions or umask of the storage folder or whatever is needed. This will be a much better developer experience then waiting for a subsequent usage of $this->handle to fail cryptically.

I'm not sure exactly what exception should be thrown here, please let me know how this can be improved.

[driesvints]

Maybe just remove the error suppression instead?