Fixup for MR #29

Resolves: rhbz#2118319

clang.spec

@@ -360,10 +360,15 @@ mv ../clang-%{compat_ver}.src ../clang
 
 %endif
 
+# TODO: Drop the HAVE_CXX_ATOMICS64_WITHOUT_LIB once clang15 is in the buildroot. It looks like
+# previously clang emitted __atomic_load for std::atomic<double>, which is not detected by cmake.
 # We set CLANG_DEFAULT_PIE_ON_LINUX=OFF to match the default used by Fedora's GCC.
 # See https://bugzilla.redhat.com/show_bug.cgi?id=2134146
 %cmake  -G Ninja \
-	-DCLANG_DEFAULT_PIE_ON_LINUX=OFF
+%ifarch %ix86
+	-DHAVE_CXX_ATOMICS64_WITHOUT_LIB=OFF \
+%endif
+	-DCLANG_DEFAULT_PIE_ON_LINUX=OFF \
 	-DLLVM_PARALLEL_LINK_JOBS=1 \
 	-DLLVM_LINK_LLVM_DYLIB:BOOL=ON \
 	-DCMAKE_BUILD_TYPE=RelWithDebInfo \