Add back UTF-32 for now and fix a MSVC build issue

patches/vscomp.patch

 diff --git a/source/common/locmap.c b/source/common/locmap.c
 index c746ce3..224a2b1 100644
 --- a/source/common/locmap.c
 +++ b/source/common/locmap.c
 @@ -29,6 +29,7 @@
  #include "cstring.h"
  #include "cmemory.h"
  
 +#if 0
  #if U_PLATFORM == U_PF_WINDOWS && defined(_MSC_VER) && (_MSC_VER >= 1500)
@@ skipping 32 matching lines @@
 +++ b/source/i18n/dtfmtsym.cpp
 @@ -169,7 +169,7 @@ SharedDateFormatSymbols::~SharedDateFormatSymbols() {
  template<> U_I18N_API
  const SharedDateFormatSymbols *
          LocaleCacheKey<SharedDateFormatSymbols>::createObject(
 -                const void */*unusedContext*/, UErrorCode &status) const {
 +                const void * /*unusedContext*/, UErrorCode &status) const {
      char type[256];
      Calendar::getCalendarTypeFromLocale(fLoc, type, UPRV_LENGTHOF(type), status);
      if (U_FAILURE(status)) {
+diff --git a/source/common/sharedobject.h b/source/common/sharedobject.h
+index 4402869..e5062cc 100644
+--- a/source/common/sharedobject.h
++++ b/source/common/sharedobject.h
+@@ -21,7 +21,7 @@ U_NAMESPACE_BEGIN
+  * update cache metrics. No other part of ICU, except for SharedObject,
+  * should directly call the methods of this base class.
+  */
+-class UnifiedCacheBase : public UObject {
++class U_COMMON_API UnifiedCacheBase : public UObject {
+ public:
+     UnifiedCacheBase() { }
+