[libc][complex] check that cfloat128 is not defined as _Complex long double

[Sh0g0-1758]

Fix buildbot errors in #118671

[Sh0g0-1758]

cc: @lntue

[llvmbot]

@llvm/pr-subscribers-libc

Author: Shourya Goel (Sh0g0-1758)

Changes

Fix buildbot errors in #118671

---

Full diff: https://github.com/llvm/llvm-project/pull/119324.diff

1 Files Affected:

• (modified) libc/src/__support/complex_type.h (+4)

diff --git a/libc/src/__support/complex_type.h b/libc/src/__support/complex_type.h
index 4c861b05bc752c..7d9f21229fa94e 100644
--- a/libc/src/__support/complex_type.h
+++ b/libc/src/__support/complex_type.h
@@ -37,10 +37,12 @@ template <> struct make_complex<float16> {
 };
 #endif
 #if defined(LIBC_TYPES_HAS_CFLOAT128)
+#if (LDBL_MANT_DIG != 113)
 template <> struct make_complex<float128> {
   using type = cfloat128;
 };
 #endif
+#endif
 
 template <typename T> using make_complex_t = typename make_complex<T>::type;
 
@@ -62,10 +64,12 @@ template <> struct make_real<cfloat16> {
 };
 #endif
 #if defined(LIBC_TYPES_HAS_CFLOAT128)
+#if (LDBL_MANT_DIG != 113)
 template <> struct make_real<cfloat128> {
   using type = float128;
 };
 #endif
+#endif
 
 template <typename T> using make_real_t = typename make_real<T>::type;