[llvm] [TLI] Return LibFunc from TargetLibraryInfo::getLibFunc (PR #217561)

[Nikita Popov via llvm-commits]

================
@@ -286,15 +290,14 @@ class TargetLibraryInfo {
       disableAllFunctions();
     else {
       // Disable individual libc/libm calls in TargetLibraryInfo.
-      LibFunc LF;
       AttributeSet FnAttrs = (*F)->getAttributes().getFnAttrs();
       for (const Attribute &Attr : FnAttrs) {
         if (!Attr.isStringAttribute())
           continue;
         auto AttrStr = Attr.getKindAsString();
         if (!AttrStr.consume_front("no-builtin-"))
           continue;
-        if (getLibFunc(AttrStr, LF))
+        if (LibFunc LF = getLibFunc(AttrStr); LF != NotLibFunc)
----------------
nikic wrote:

```suggestion
        if (LibFunc LF = getLibFunc(AttrStr))
```
Does this work (NotLibFunc is 0)?

https://github.com/llvm/llvm-project/pull/217561