[llvm] Optionally print `!prof` metadata inline (PR #130303)

[Peter Collingbourne via llvm-commits]

pcc wrote:

It may be more generally useful to have a flag for printing instruction and GV metadata inline (one level of expansion) instead of having a special case for `!prof`. This could also be useful for CFI, e.g.
```
@foo = constant i32 0, type !12345
!12345 = !{i64 0, !"foo"}
```
becomes
```
@foo = constant i32 0, !type !{i64 0, !"foo"}
```
IIRC inline metadata is parsed as expected so this could be useful for developers who are manually editing metadata e.g. for test cases.

https://github.com/llvm/llvm-project/pull/130303