Add sw_64 support

[haomi123]

Add sw_64 support

[AlexPeshkoff]

Did you try to run tests in extern/libcds? That's HW-dependent library, and I want to make sure does it work correctly on sw-64. Malfunction of it may cause unstable FB operation.

[mariuz]

@haomi123 here is example for LoongArch patch for libcds in the firebird tree

fcc471e#diff-31135add04bb8d8584529be04bae88c6a088d3a90c73a6c8c7716bd8bec815db

also upstream pull request
khizmax/libcds#183

ps : @AlexPeshkoff upstream project seems to be unmaintained
https://github.com/khizmax/libcds/pulls

[AlexPeshkoff]

@mariuz I know that libcds is unmaintained. Not good, but not too big trouble - we already have unmaintained btyacc and it did not cause too big troubles for >10 years. And IMO it's not a reason to skip it's tests when porting to new hardware. For S390x & mentioned here LoongArch tests were reported to pass successfully.