[v6,0/9] make rte_intr_handle internal

  Moving struct rte_intr_handle as an internal structure to
avoid any ABI breakages in future. Since this structure defines
some static arrays and changing respective macros breaks the ABI.
Eg:
Currently RTE_MAX_RXTX_INTR_VEC_ID imposes a limit of maximum 512
MSI-X interrupts that can be defined for a PCI device, while PCI
specification allows maximum 2048 MSI-X interrupts that can be used.
If some PCI device requires more than 512 vectors, either change the
RTE_MAX_RXTX_INTR_VEC_ID limit or dynamically allocate based on
PCI device MSI-X size on probe time. Either way its an ABI breakage.

Change already included in 21.11 ABI improvement spreadsheet (item 42):
https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.google.com_s
preadsheets_d_1betlC000ua5SsSiJIcC54mCCCJnW6voH5Dqv9UxeyfE_edit-23gid-
3D0&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=5ESHPj7V-7JdkxT_Z_SU6RrS37ys4U
XudBQ_rrS5LRo&m=7dl3OmXU7QHMmWYB6V1hYJtq1cUkjfhXUwze2Si_48c&s=lh6DEGhR
Bg1shODpAy3RQk-H-0uQx5icRfUBf9dtCp4&e=

This series makes struct rte_intr_handle totally opaque to the outside
world by wrapping it inside a .c file and providing get set wrapper APIs
to read or manipulate its fields.. Any changes to be made to any of the
fields should be done via these get set APIs.
Introduced a new eal_common_interrupts.c where all these APIs are defined
and also hides struct rte_intr_handle definition.

v1:
* Fixed freebsd compilation failure
* Fixed seg fault in case of memif

v2:
* Merged the prototype and implementation patch to 1.
* Restricting allocation of single interrupt instance.
* Removed base APIs, as they were exposing internally
allocated memory information.
* Fixed some memory leak issues.
* Marked some library specific APIs as internal.

v3:
* Removed flag from instance alloc API, rather auto detect
if memory should be allocated using glibc malloc APIs or
rte_malloc*
* Added APIs for get/set windows handle.
* Defined macros for repeated checks.

v4:
* Rectified some typo in the APIs documentation.
* Better names for some internal variables.

v5:
* Reverted back to passing flag to instance alloc API, as
with auto detect some multiprocess issues existing in the
library were causing tests failure.
* Rebased to top of tree.

v6:
* renamed RTE_INTR_INSTANCE_F_UNSHARED as RTE_INTR_INSTANCE_F_PRIVATE,
* changed API and removed need for alloc_flag content exposure
  (see rte_intr_instance_dup() in patch 1 and 2),
* exported all symbols for Windows,
* fixed leak in unit tests in case of alloc failure,
* split (previously) patch 4 into three patches
  * (now) patch 4 only concerns alarm and (previously) patch 6 cleanup bits
    are squashed in it,
  * (now) patch 5 concerns other libraries updates,
  * (now) patch 6 concerns drivers updates:
    * instance allocation is moved to probing for auxiliary,
    * there might be a bug for PCI drivers non requesting
      RTE_PCI_DRV_NEED_MAPPING, but code is left as v5,
* split (previously) patch 5 into three patches
  * (now) patch 7 only hides structure, but keep it in a EAL private
    header, this makes it possible to keep info in tracepoints,
  * (now) patch 8 deals with VFIO/UIO internal fds merge,
  * (now) patch 9 extends event list,