Suppress Wunreachable-code in floating matchers and exception tests

Closes #1350

include/internal/catch_matchers_floating.cpp

@@ -104,6 +104,12 @@ namespace Floating {
         }
     }
 
+#if defined(__clang__)
+#pragma clang diagnostic push
+// Clang <3.5 reports on the default branch in the switch below
+#pragma clang diagnostic ignored "-Wunreachable-code"
+#endif
+
     bool WithinUlpsMatcher::match(double const& matchee) const {
         switch (m_type) {
         case FloatingPointKind::Float:
@@ -115,6 +121,10 @@ namespace Floating {
         }
     }
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
     std::string WithinUlpsMatcher::describe() const {
         return "is within " + Catch::to_string(m_ulps) + " ULPs of " + ::Catch::Detail::stringify(m_target) + ((m_type == FloatingPointKind::Float)? "f" : "");
     }

projects/SelfTest/UsageTests/Exception.tests.cpp

@@ -18,6 +18,7 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wweak-vtables"
 #pragma clang diagnostic ignored "-Wmissing-noreturn"
+#pragma clang diagnostic ignored "-Wunreachable-code"
 #endif
 
 namespace { namespace ExceptionTests {