cmake: Use 80-bit libm function definitions.

dios/CMakeLists.txt

@@ -25,7 +25,7 @@ file( GLOB SRC_dios_native arch/native/*.cpp arch/native/*.c )
 file( GLOB SRC_librst rst/*.cpp )
 file( GLOB SRC_libc libc/*/*.c )
 file( GLOB SRC_libc_cpp libc/*/*.cpp )
-file( GLOB SRC_libm libm/*.c )
+file( GLOB SRC_libm libm/*.c libm/ld80/*.c )
 file( GLOB SRC_libcxxabi libcxxabi/src/*.cpp )
 file( GLOB SRC_libcxx libcxx/src/*.cpp  )
 file( GLOB SRC_libpthread libpthread/*.cpp )