mlang: Implement IMultiLanguage2_IsCodePageInstallable.

[Hans Leidekker]

diff --git a/dlls/mlang/mlang.c b/dlls/mlang/mlang.c
index 180e1ad..e257aaf 100644
--- a/dlls/mlang/mlang.c
+++ b/dlls/mlang/mlang.c
@@ -3125,8 +3125,37 @@ static HRESULT WINAPI fnIMultiLanguage2_IsCodePageInstallable(
     IMultiLanguage3* iface,
     UINT uiCodePage)
 {
-    FIXME("%u\n", uiCodePage);
-    return E_NOTIMPL;
+    UINT i;
+    static const UINT cp[] =
+    {
+        37, 437, 500, 708, 720, 737, 775, 850, 852,
+        855, 857, 858, 860, 861, 862, 863, 864, 865,
+        866, 869, 870, 874, 875, 932, 936, 949, 950,
+        1026, 1047, 1140, 1141, 1142, 1143, 1144, 1145,
+        1146, 1147, 1148, 1149, 1200, 1201, 1250, 1251,
+        1252, 1253, 1254, 1255, 1256, 1257, 1258, 1361,
+        10000, 10001, 10002, 10003, 10004, 10005, 10006,
+        10007, 10008, 10010, 10017, 10021, 10029, 10079,
+        10081, 10082, 20000, 20001, 20002, 20003, 20004,
+        20005, 20105, 20106, 20107, 20108, 20127, 20261,
+        20269, 20273, 20277, 20278, 20280, 20284, 20285,
+        20290, 20297, 20420, 20423, 20424, 20833, 20838,
+        20866, 20871, 20880, 20905, 20924, 20932, 20936,
+        20949, 21025, 21027, 21866, 28591, 28592, 28593,
+        28594, 28595, 28596, 28597, 28598, 28599, 28603,
+        28605, 38598, 50000, 50001, 50220, 50221, 50222,
+        50225, 50227, 50229, 50930, 50931, 50932, 50933,
+        50935, 50936, 50937, 50939, 50949, 50950, 51251,
+        51253, 51256, 51932, 51936, 51949, 52936, 54936,
+        57002, 57003, 57004, 57005, 57006, 57007, 57008,
+        57009, 57010, 57011, 65000, 65001
+    };
+
+    TRACE("%u\n", uiCodePage);
+
+    if (uiCodePage == 29001) return S_FALSE;
+    for (i = 0; i < sizeof(cp)/sizeof(cp[0]); i++) if (uiCodePage == cp[i]) return S_OK;
+    return E_INVALIDARG;
 }
 
 static HRESULT WINAPI fnIMultiLanguage2_SetMimeDBSource(