[clang] [NFC] Reduce size of FunctionEffect to 1 byte. (PR #100753)

[via cfe-commits]

================
@@ -4699,16 +4699,16 @@ class FunctionEffect {
 
 private:
   LLVM_PREFERRED_TYPE(Kind)
-  unsigned FKind : 3;
+  uint8_t FKind : 3;
----------------
Sirraide wrote:

I mean, if this is the only field, then can’t we just make the actual type of this `Kind` since that’s a `uint8_t` enum anyway? Or is it likely that we’ll be adding more fields to this soon?

https://github.com/llvm/llvm-project/pull/100753