[OpenMP][Map][NFC] improve map chain. (#101903)

This is for mapping structure has data members, which have 'default'
mappers, where needs to map these members individually using
their 'default' mappers.

example map(tofrom: spp[0][0]), look at test case.

currently create 6 maps:
1>&spp, &spp[0],  size 8, maptype TARGET_PARAM | FROM | TO
2>&spp[0], &spp[0][0], size(D)with maptype OMP_MAP_NONE, nullptr
3>&spp[0], &spp[0][0].e, size(e) with maptype MEMBER_OF  | FROM  | TO
4>&spp[0], &spp[0][0].h, size(h) with maptype MEMBER_OF  | FROM  | TO
5>&spp, &spp[0],size(8), maptype MEMBER_OF | IMPLICIT | FROM  | TO
6>&spp[0], &spp[0][0].f size(D) with maptype MEMBER_OF |IMPLICIT
|PTR_AND_OBJ, @.omp_mapper._ZTS1C.default

maptype with/without OMP_MAP_PTR_AND_OBJ
   For "2" and "5", since it is mapping pointer and pointee pair,
   PTR_AND_OBJ should be set
   But for "6" the PTR_AND_OBJ should not set.
However, "5" is duplicate with "1" can be skip.

To fix "2", during the call to emitCombinEntry with false with
NotTargetParams
instead !PartialStruct.PreliminaryMapData.BasePointers.empty(), since
all captures need to be TARGET_PARAM
And inside emitCombineEntry:  check
!PartialStruct.PreliminaryMapData.BasePointers.empty() to set
PTR_AND_OBJ

For "5" and "6": the fix in generateInfoForComponentList:
Add new variable IsPartialMapped set with
!PartialStruct.PreliminaryMapData.BasePointers.empty();

When that is true, skip generate "5" and don"t set IsExpressionFirstInfo
to false, so that PTR_AND_OBJ would be set.

After fix: will have 5 maps instead 6
1>&spp, &spp[0],  size 8, maptype TARGET_PARAM | FROM | TO
2>&spp[0], &spp[0][0], size(D), maptype PTR_AND_OBJ, nullptr
3>&spp[0], &spp[0][0].e, size(e), maptype MEMBER_OF_2  | FROM  | TO
4>&spp[0], &spp[0][0].h, size(h), maptype MEMBER_OF_2  | FROM  | TO
5>&spp[0], &spp[0][0].f size(32), maptype MEMBER_OF_2 | IMPLICIT,
@.omp_mapper._ZTS1C.default

For map(sppp[0][0][0]):
after fix: will have 6 maps instead 8.

https://github.com/llvm/llvm-project/pull/101903