targets/egl: Add SConscript for egl-apis.

It will build api_OpenVG.dll on Windows.

src/gallium/targets/SConscript

@@ -33,6 +33,7 @@ if 'xorg' in env['statetrackers']:
 if 'egl' in env['statetrackers']:
 	SConscript([
 		'egl-swrast/SConscript',
+		'egl-apis/SConscript',
 	])
 
 # Ideally all non-target directories would produce convenience

src/gallium/targets/egl-apis/SConscript

@@ -0,0 +1,33 @@
+#######################################################################
+# SConscript for egl-apis target
+
+Import('*')
+
+if env['platform'] == 'windows':
+
+    env = env.Clone()
+
+    env.Append(CPPPATH = [
+            '#/src/gallium/state_trackers/vega',
+    ])
+
+    env.Append(LIBS = [
+        'gdi32',
+        'user32',
+        'kernel32',
+        'ws2_32',
+    ])
+
+    env['no_import_lib'] = 1
+
+    api_libs = {
+        'OpenVG': vgapi + st_vega,
+    }
+
+    for name in api_libs.keys():
+        api = env.SharedLibrary(
+            target = 'api_' + name,
+            source = ['api_' + name + '.c'],
+            LIBS = api_libs[name] + gallium + env['LIBS'],
+        )
+        env.InstallSharedLibrary(api)