[SR-9337] SwiftSyntax not getting code generation releases automatically

[jpsim]

Previous ID	SR-9337
Radar	None
Original Reporter	@jpsim
Type	Bug

Additional Detail from JIRA

Votes	0
Component/s	Project Infrastructure, SwiftSyntax
Labels	Bug
Assignee	None
Priority	Medium

md5: d409dea74a1d59a0249fbbe7888bf988

Issue Description:

From the SwiftSyntax README:

Swift-CI will automatically run the code generation step whenever a new toolchain (development snapshot or release) is published. It should thus almost never be necessary to perform the above build yourself.

However, this appears to have only worked once:

$ git tag --list
0.40200.0
swift-4.2-DEVELOPMENT-SNAPSHOT-2018-08-25-a
swift-DEVELOPMENT-SNAPSHOT-2018-08-25-a

This makes it hard to use SwiftSyntax using the Swift Package Manager with any changes that have been merged in the last 3 months.

[belkadan]

cc @akyrtzi

[akyrtzi]

cc @nkcsgexi