attempt to fix windows build

src/copy/pvArrayPlugin.cpp

@@ -5,6 +5,7 @@
 
 #include <stdlib.h>
 
+#define epicsExportSharedSymbols
 #include <pv/pvArrayPlugin.h>
 #include <pv/convert.h>
 #include <pv/pvSubArrayCopy.h>

src/copy/pvDeadbandPlugin.cpp

@@ -4,6 +4,7 @@
  */
 #include <stdlib.h>
 
+#define epicsExportSharedSymbols
 #include <pv/pvDeadbandPlugin.h>
 #include <pv/convert.h>
 #include <pv/pvSubArrayCopy.h>

src/copy/pvPlugin.cpp

@@ -2,6 +2,8 @@
 /*
  * The License for this software can be found in the file LICENSE that is included with the distribution.
  */
+
+#define epicsExportSharedSymbols
 #include <pv/pvPlugin.h>
 
 using namespace epics::pvData;

src/copy/pvTimestampPlugin.cpp

@@ -2,7 +2,7 @@
 /*
  * The License for this software can be found in the file LICENSE that is included with the distribution.
  */
-
+#define epicsExportSharedSymbols
 #include <pv/pvTimestampPlugin.h>
 #include <pv/convert.h>
 #include <pv/pvCopy.h>