[SR-15688] Improve Parser Recovery and Diagnostics for Import Paths with Operators in Them

[CodaFi]

Previous ID	SR-15688
Radar	rdar://problem/87159294
Original Reporter	@CodaFi
Type	Improvement
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Improvement, Parser, StarterBug
Assignee	@angela-laar
Priority	Medium

md5: d8dd3d94d5f74900b7099a089ec5b725

Issue Description:

These have never once worked, so we ought to do a better job of detecting and diagnosing them. Right now operator folding kicks in and we just get a cascade of bad errors

import func SwiftUI.Text.== 
// Consecutive statements on a line must be separated by ';'
// Operator with postfix spacing cannot start a subexpression
// Expected expression
// 'Text' was imported as 'func', but it is a struct
//  Operator with postfix spacing cannot start a subexpression

Right after we call parseAnyIdentifier in parseImportDecl would be the right place to check, diagnose, and delete these operator components.

[CodaFi]

@swift-ci create

[angela-laar]

PR has been reviewed: #40836

[CodaFi]

Excellent branch name.

[angela-laar]

Thanks 🙂