[SR-9660] -emit-sib -o - emits invalid bitcode

[gottesmm]

Previous ID	SR-9660
Radar	None
Original Reporter	@gottesmm
Type	Task

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Task
Assignee	None
Priority	Medium

md5: b6a75f96ae83ab8304b799c2183f5ad1

Issue Description:

I discovered this while working on: #21822 in the sil-func-extractor test that I modified in that PR. If we output in that test to file, we correctly emit a properly formed sib file. If we go through stdout with -o -, we do not get a sib header and in fact llvm-bc-analyzer says there is a bad top level record.