Rewrite the 64bit test. Fixes #131
Rewrite the 64bit test. Fixes #131

The old test was not working at all and was failing on both 32 and 64
bit systems with

configure:13545: checking size of long is longer than 32 bit
configure:13561: gcc -c -g -O2 -Wall -Wcast-qual -Wchar-subscripts
-Wmissing-prototypes -Wmissing-declarations -Wno-error=cast-align
conftest.c >&5
conftest.c: In function 'main':
conftest.c:32:34: error: 'dummy' undeclared (first use in this function)
 switch (0) case 0: case (sizeof (dummy) >= 8):;
                                  ^
conftest.c:32:34: note: each undeclared identifier is reported only once
for each function it appears in

mouse07410/asn1c,khmseu/asn1c,khmseu/asn1c,mouse07410/asn1c,khmseu/asn1c,khmseu/asn1c,mouse07410/asn1c,mouse07410/asn1c