Only use warnings-as-errors on msvc, gcc, clang

test/Jamfile

@@ -361,4 +361,8 @@ compile-fail shared_from_fail.cpp ;
 compile-fail weak_from_fail.cpp ;
 
 compile sp_override_test.cpp ;
-compile sp_pedantic_test.cpp : <warnings>pedantic <warnings-as-errors>on ;
+compile sp_pedantic_test.cpp
+  : <warnings>pedantic
+    <toolset>msvc:<warnings-as-errors>on
+    <toolset>gcc:<warnings-as-errors>on
+    <toolset>clang:<warnings-as-errors>on ;