[clang] [Sema] -Wpointer-bool-conversion: suppress lambda function pointer conversion diagnostic during instantiation (PR #83497)

[David Blaikie via cfe-commits]

dwblaikie wrote:

Presumably similar things might show up in macros? But can cross that bridge when we come to it.

Perhaps we have some/could use some generic utility for this sort of contextual warning "if these things are literally written next to each other, warn, but if they came to be via template instantiation, macro, (something else?) then don't" because that sort of situation shows up pretty regularly in diagnostics, I think... 

https://github.com/llvm/llvm-project/pull/83497