[compiler-rt] Found one more delta to unbreak build for z/os (PR #82789)

[Alexander Richardson via llvm-commits]

================
@@ -368,10 +368,11 @@ static __inline fp_t __compiler_rt_fmax(fp_t x, fp_t y) {
 #endif
 }
 
-#elif defined(QUAD_PRECISION) && defined(CRT_HAS_TF_MODE)
+#elif defined(QUAD_PRECISION)
+#if defined(CRT_HAS_TF_MODE)
+#if defined(CRT_HAS_IEEE_TF)
----------------
arichardson wrote:

```suggestion
#if defined(CRT_HAS_IEEE_TF) && defined(CRT_HAS_INT128)
```
Could we simplify this to just be 
```
#if defined(CRT_HAS_IEEE_TF) && defined(CRT_HAS_INT128)
...
#elif defined(CRT_LDBL_128BIT)
...
#else
#error Unsupported TF mode type  
#endif
```

https://github.com/llvm/llvm-project/pull/82789