Tools: check for feenableexcept on WAF

Tools/ardupilotwaf/boards.py

@@ -362,6 +362,7 @@ class sitl(Board):
         ]
 
         cfg.check_librt(env)
+        cfg.check_feenableexcept()
 
         env.LINKFLAGS += ['-pthread',]
         env.AP_LIBRARIES += [

Tools/ardupilotwaf/cxx_checks.py

@@ -169,6 +169,22 @@ def check_librt(cfg, env):
 
     return ret
 
+@conf
+def check_feenableexcept(cfg):
+
+    cfg.check(
+        compiler='cxx',
+        fragment='''
+        #include <fenv.h>
+
+        int main() {
+            return feenableexcept(FE_OVERFLOW | FE_DIVBYZERO);
+        }''',
+        msg="Checking for feenableexcept",
+        define_name="HAVE_FEENABLEEXCEPT",
+        mandatory=False,
+    )
+
 @conf
 def check_package(cfg, env, libname):
     '''use pkg-config to look for an installed library that has a LIBNAME.pc file'''