enable maxDescriptors on Illumos/Solaris (#19295)

Author: BarrOff

lib/pure/asyncdispatch.nim

@@ -1974,11 +1974,11 @@ when defined(posix):
   import posix
 
 when defined(linux) or defined(windows) or defined(macosx) or defined(bsd) or
-       defined(zephyr) or defined(freertos):
+       defined(solaris) or defined(zephyr) or defined(freertos):
   proc maxDescriptors*(): int {.raises: OSError.} =
     ## Returns the maximum number of active file descriptors for the current
     ## process. This involves a system call. For now `maxDescriptors` is
-    ## supported on the following OSes: Windows, Linux, OSX, BSD.
+    ## supported on the following OSes: Windows, Linux, OSX, BSD, Solaris.
     when defined(windows):
       result = 16_700_000
     elif defined(zephyr) or defined(freertos):

lib/pure/selectors.nim

@@ -324,11 +324,11 @@ else:
     doAssert(timeout >= -1, "Cannot select with a negative value, got: " & $timeout)
 
   when defined(linux) or defined(windows) or defined(macosx) or defined(bsd) or
-       defined(zephyr) or defined(freertos):
+       defined(solaris) or defined(zephyr) or defined(freertos):
     template maxDescriptors*(): int =
       ## Returns the maximum number of active file descriptors for the current
       ## process. This involves a system call. For now `maxDescriptors` is
-      ## supported on the following OSes: Windows, Linux, OSX, BSD.
+      ## supported on the following OSes: Windows, Linux, OSX, BSD, Solaris.
       when defined(windows):
         16_700_000
       elif defined(zephyr) or defined(freertos):