libpvxsIoc symbol conflicts with libqsrv

[mdavidsaver]

areaDetector/ADCore#532 reports symbol conflicts relating to PVA link support.

• dbpvar
• pvaLinkNWorkers
• pvar_jlif_lsetPVA

[mdavidsaver]

Conflicts should be resolved by 8c07933.

Testing with:

PROD_IOC = pvp
# pvp.dbd will be created and installed
DBD += pvp.dbd

# pvp.dbd will be made up from these files:
pvp_DBD += base.dbd
pvp_DBD += pvxsIoc.dbd
pvp_DBD += PVAServerRegister.dbd qsrv.dbd

# Add all the support libraries needed by this IOC
pvp_LIBS += qsrv $(EPICS_BASE_PVA_CORE_LIBS)
pvp_LIBS += pvxsIoc

# pvp_registerRecordDeviceDriver.cpp derives from pvp.dbd
pvp_SRCS += pvp_registerRecordDeviceDriver.cpp

Links and loads. On startup, prints:

INFO: PVXS QSRV2 is loaded, NOT permitted, and disabled.
      Not permitted due to conflict with QSRV1.
      Remove qsrv.dbd from IOC.

However, I realize that the selection of which pva link implementation is based on DBD file order, so if both QSRV1+2 are included, and pvxsIoc.dbd is listed first, then the QSRV2 implementation will be used, but without the diagnostic IOC shell tools.

[mdavidsaver]

Thinking it over, I realize that renaming lsetPVA to lsetPVX is an public ABI change since that symbol name appears in pvxsIoc.dbd. This means that the next release will have to be 1.5.0 instead of 1.4.2.