Go CodeGen should address the errors and warnings from TCGC

[lirenhe]

We need to empower our customers both internal and external to easily trouble shooting and fix spec issues that would block the CodeGen.

Today, TCGC could already do the check on the patterns and results from TypeSpec compiler and reports warning and errors for the unsupported case and invalid usage.

However, our CodeGen didn't address those errors and warnings from TCGC in the implementation and in most cases would continue the codegen which would result in unexpected generated code & error. When that happens, the outcome would be difficult to trouble shooting.

Proposals:

• Go CodeGen need to display those warnings and errors in the command line output instead of ignoring them.
• Go CodeGen should properly address the errors and warnings to provide a better user experience.

[tadelesh]

tcgc issue here: Azure/typespec-azure#1487.
java impl reference: microsoft/typespec#4382.

[jhendrixMSFT]

Regarding "Go CodeGen should properly address the errors and warnings to provide a better user experience.", does this mean we need to do something more that just context.program.reportDiagnostics(sdkContext.diagnostics);?

[jhendrixMSFT]

Also, is there a reason why tcgc's createSdkContext() can't report the diagnostics? It should have access to the context.program to do so. This way, emitters don't have to do it (they all get it for free).