[flang] add no-cpp-dep test for AIX 64 bit (#74637)

Add a new test for no-cpp-dep on AIX as it requires 64 bit OBJECT_MODE
since only 64-bit AIX is supported. AIX does not allow `-o /dev/null`
and requires `-lpthread` flag to be added.

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Co-authored-by: Mark Danial <mark.danial@ibm.com>