[libc] [llvm] [libc][math][c23] Add fmaf16 C23 math function. (PR #130757)

[via llvm-commits]

================
@@ -3562,6 +3562,21 @@ add_fp_unittest(
     libc.src.__support.macros.properties.types
 )
 
+add_fp_unittest(
+  fmaf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    fmaf16_test.cpp
+  HDRS
+    FmaTest.h
+  DEPENDS
+    libc.src.math.fmaf16
+    libc.src.__support.CPP.type_traits
+    libc.src.__support.FPUtil.cast
+    libc.src.__support.macros.properties.types
----------------
overmighty wrote:

```suggestion
    libc.src.__support.FPUtil.cast
```

https://github.com/llvm/llvm-project/pull/130757