AIX: add additional HostMemoryInfo metrics (#188)

For AIX 7.2, the perfstat_memory_total interface includes additional metrics.
This change adds those metrics to `types.HostMemoryInfo.Metrics` in the AIX provider.

The new attributes being added are:

- bytes_coalesced - Number of bytes of the calling partition’s logical real memory coalesced
- bytes_coalesced_mempool - Number of bytes of logical real memory coalesced in the calling partition’s memory pool if the calling partition is authorized to see pool wide statistics else, set to zero.
- real_pinned - Amount of pinned memory in bytes.
- pgins - Number of pages paged in .
- pgouts - Number of pages paged out.
- pgsp_free - Amount of free paging space in bytes.
- pgsp_rsvd - Amount of reserved paging space in bytes.

Reference: https://www.ibm.com/docs/en/aix/7.2?topic=interfaces-perfstat-memory-total-interface

---------

Co-authored-by: Ahmet SALIH <[email protected]>

.changelog/188.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+aix: Added mappings for AIX host memory information
+```

providers/aix/host_aix_ppc64.go

@@ -115,6 +115,16 @@ func (*host) Memory() (*types.HostMemoryInfo, error) {
 	mem.VirtualFree = mem.Free + uint64(meminfo.pgsp_free)*pagesize
 	mem.VirtualUsed = mem.VirtualTotal - mem.VirtualFree
 
+	mem.Metrics = map[string]uint64{
+		"bytes_coalesced":         uint64(meminfo.bytes_coalesced),
+		"bytes_coalesced_mempool": uint64(meminfo.bytes_coalesced_mempool),
+		"real_pinned":             uint64(meminfo.real_pinned) * pagesize,
+		"pgins":                   uint64(meminfo.pgins),
+		"pgouts":                  uint64(meminfo.pgouts),
+		"pgsp_free":               uint64(meminfo.pgsp_free) * pagesize,
+		"pgsp_rsvd":               uint64(meminfo.pgsp_rsvd) * pagesize,
+	}
+
 	return &mem, nil
 }