W32: Link GTK to pangowin32

Needed for pango_win32_font_logfont() from gtkimcontextime.

https://bugzilla.gnome.org/show_bug.cgi?id=773299

gtk/meson.build

@@ -894,7 +894,8 @@ endif
 
 if win32_enabled
   gtk_cargs += ['-DGTK_PRINT_BACKENDS="file,lpr"']
-  gtk_deps += [ giowin32_dep ]
+  gtk_deps += [ giowin32_dep, pangowin32_dep ]
+
   gtk_deps += [cc.find_library('advapi32'),
                cc.find_library('comctl32'),
                cc.find_library('dwmapi'),

meson.build

@@ -349,6 +349,11 @@ if pangoft_dep.found()
   endif
 endif
 
+if win32_enabled
+  # for GTK_IM_CONTEXT_IME
+  pangowin32_dep  = dependency('pangowin32')
+endif
+
 pangocairo_dep = dependency('pangocairo', version: cairo_req,
                             fallback : ['pango', 'libpangocairo_dep'])
 pixbuf_dep     = dependency('gdk-pixbuf-2.0', version: gdk_pixbuf_req,