meson: fix dl detection on non cygwin windows

v4: - Don't run checks on Windows that will always fail

Reviewed-by: Eric Anholt <eric@anholt.net> (v3)
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
diff --git a/meson.build b/meson.build
index 65afcb4..c700d64 100644
--- a/meson.build
+++ b/meson.build
@@ -1113,14 +1113,15 @@
 endif
 
 # check for dl support
-if cc.has_function('dlopen')
-  dep_dl = null_dep
-else
-  dep_dl = cc.find_library('dl')
-endif
-if cc.has_function('dladdr', dependencies : dep_dl)
-  # This is really only required for megadrivers
-  pre_args += '-DHAVE_DLADDR'
+dep_dl = null_dep
+if host_machine.system() != 'windows'
+  if not cc.has_function('dlopen')
+    dep_dl = cc.find_library('dl')
+  endif
+  if cc.has_function('dladdr', dependencies : dep_dl)
+    # This is really only required for megadrivers
+    pre_args += '-DHAVE_DLADDR'
+  endif
 endif
 
 if cc.has_function('dl_iterate_phdr')