[compiler-rt] [builtins][NFC] Avoid using CRT_LDBL_128BIT in tests (PR #66832)

[Alexander Richardson via llvm-commits]

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@@ -7,7 +7,7 @@
 #include <float.h>
 #include <stdio.h>
 
-#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
+#if defined(CRT_HAS_TF_MODE)
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arichardson wrote:

This one actually fails without and IEEE float128. Right now that doesn't matter but it will start failing once CRT_HAS_TF_MODE gets set with non-IEEE TF floats (powerpc64).

https://github.com/llvm/llvm-project/pull/66832