add a whole bunch of new gcc/g++ warnings, and fix long long complaint with -pedantic

configure.in

@@ -190,7 +190,7 @@ if test "$GNU_CC"; then
     #             be a little bit stricter
     # -pipe     - speeds up the build a little by using pipes rather than
     #             temp files
-    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wall -pipe"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wall -W -Wconversion -Wshadow -Wpointer-arith -Wbad-function-cast -Wcast-align"
 
     _DEFINES_CFLAGS='-include $(DEPTH)/config-defs.h'
     _USE_CPP_INCLUDE_FLAG=1
@@ -203,7 +203,7 @@ fi
 
 if test "$GNU_CXX"; then
     # Turn on GNU specific features
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wall -pipe"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wall -W -Wconversion -Wshadow -Wpointer-arith -Wbad-function-cast -Wcast-align -Wsign-compare -Woverloaded-virtual -Wsynth -pipe"
 
     _DEFINES_CXXFLAGS='-include $(DEPTH)/config-defs.h'
     _USE_CPP_INCLUDE_FLAG=1
@@ -1315,7 +1315,7 @@ dnl Make pedantic a flag for now since the builds currently choke on it.
 MOZ_ARG_ENABLE_BOOL(pedantic,
 [  --enable-pedantic       Issue all warnings demanded by strict ANSI C ],
   [ _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -pedantic"
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -pedantic" ])
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -pedantic -Wno-long-long" ])
 
 dnl Note: This should not be disabled if --enable-oji is set
 MOZ_ARG_DISABLE_BOOL(shared,