[PATCH] Make redirection only for target_clones: V2 (PR ipa/85329).

[Martin Liška]

Hi.

I'm sending V2. The patch adjusts:
- make redirection just for target_clones, done simply by recording nodes
  where expand_target_clones return true
- reset various DECL_* flags on default version, needed for ipa-visibility assert I've seen
- handle empty string in target_clones: __attribute__((target_clones("",..
  I saw that during reduction of the ICE.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Martin