Panic on "invalid encoded numeric literal" error on 64-bit Windows

[evhan]

64-bit builds on Windows (MinGW/MSYS) fail on the lolevel tests with the error "invalid encoded numeric literal".

MSYS2:

"C:/MSYS264/home/evhan/chicken-4.12.0rc1-mingw-msys-x86-64/tests/../chicken "lolevel-tests.scm" -output-file "a.c" -types ../types.db -ignore-repository -verbose -include-path C:/MSYS264/home/evhan/chicken-4.12.0rc1-mingw-msys-x86-64/tests/.. -specialize"
""gcc" "a.c" -o "a.o" -c  -fno-strict-aliasing -fwrapv -DHAVE_CHICKEN_CONFIG_H -DC_ENABLE_PTABLES -Os -IC:/MSYS264/home/evhan/chicken-4.12.0rc1-mingw-msys-x86-64/tests/.. -IC:/MSYS264/usr/local/chicken-4.12.0rc1-mingw-msys-x86-64/include/chicken"
rm a.c
""gcc" "a.o" -o "a.out" -Wl,--enable-auto-import -LC:/MSYS264/home/evhan/chicken-4.12.0rc1-mingw-msys-x86-64/tests/.. -LC:/MSYS264/usr/local/chicken-4.12.0rc1-mingw-msys-x86-64/lib -lchicken -lm -lws2_32"
rm a.o
[panic] invalid encoded numeric literal - execution terminated

make: *** [rules.make:663: check] Error 1

And MinGW:

""gcc" "a.c" -o "a.o" -c  -fno-strict-aliasing -fwrapv -DHAVE_CHICKEN_CONFIG_H -DC_ENABLE_PTABLES -Os -IC:\\Users\\evhan\\Downloads\\chicken-4.12.0rc1-mingw-x86-64\\tests/.. -IC:/mingw-w64/usr/local/chicken-4.12.0rc1-mingw-x86-64/include/chicken"
rm a.c
""gcc" "a.o" -o "a.out" -Wl,--enable-auto-import -LC:\Users\evhan\Downloads\chicken-4.12.0rc1-mingw-x86-64\tests/.. -LC:/mingw-w64/usr/local/chicken-4.12.0rc1-mingw-x86-64/lib -lchicken -lm -lws2_32"
rm a.o
[panic] invalid encoded numeric literal - execution terminated

.\rules.make:665: recipe for target 'check' failed
mingw32-make: *** [check] Error 1

This was observed on an x86-64 Windows 7 VM. Cygwin and 32-bit MinGW builds are unaffected.