[glibc/azanella/clang] math: Fix isgreater* and isless* for clang

[Adhemerval Zanella]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=1d8bf2430ed01495573dfe13e97168f4f7013a11

commit 1d8bf2430ed01495573dfe13e97168f4f7013a11
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Fri Apr 1 16:35:32 2022 -0300

    math: Fix isgreater* and isless* for clang
    
    clang does not check for unordered numbers with builtins for
    _Float128 type.

Diff:
---
 math/math.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/math/math.h b/math/math.h
index 6dc0604132..db5763ec00 100644
--- a/math/math.h
+++ b/math/math.h
@@ -1295,7 +1295,7 @@ iszero (__T __val)
 #endif
 
 #ifdef __USE_ISOC99
-# if __GNUC_PREREQ (3, 1)
+# if __GNUC_PREREQ (3, 1) && !defined __clang__
 /* ISO C99 defines some macros to compare number while taking care for
    unordered numbers.  Many FPUs provide special instructions to support
    these operations.  Generic support in GCC for these as builtins went