(TPFUG) > 2042 TOD support - New APIs to assist in remediation strategies

The STCK/STCKF 8 byte format TOD will wrap in 2042. To help customers remediate issues in their code as early as possible and to avoid customers writing additional code that subsequently needs remediation, we would like IBM to provide new datatype and function support to assist with two specific remediation strategies. 

1) "8 byte TOD bracketing support" (8 byte TOD format and if bit 0 is 0 then assume TOD has wrapped

- create a new data type for a bracketed 8 byte TOD. Main benefits would be so that it was clearer in code when a bracketed TOD was being used and so that a bit field defintion for bit 0  could be created to make tests for a wrapped TOD easier. 

- Create a function similar to tpf_STCK_to_timet that supports passing in a bracketed 8 byte TOD. Convert the passed 8 byte TOD to a STCKE format and if bit 0 of the passed TOD is 0 then set the epoch byte to 1. Could consider just enhancing the existing function but a different function name would help identify cases where bracketed TOD values were being supported.

- Provide macros such as a LT test on two bracketed TODs (much like STCKE_LT etc macros in c_stcke.h) with assembler equivalent (inline macro that could be used in the CP as well as e-types)

2) Alternative 8 byte TOD format that is 1 byte epoch + 7 bytes of STCK format TOD

- define a new TOD data type for this format

- provide new APIs to convert this new type to a time_t and a time_t to this new type