Quiet a few MSC compiler warnings.

Author: adunstan

src/backend/catalog/objectaddress.c

@@ -1360,4 +1360,6 @@ get_object_property_data(Oid class_id)
 
 	ereport(ERROR,
 			(errmsg_internal("unrecognized class id: %u", class_id)));
+
+	return NULL; /* keep MSC compiler happy */
 }

src/backend/optimizer/path/costsize.c

@@ -68,6 +68,9 @@
 
 #include "postgres.h"
 
+#ifdef _MSCVER
+#include <float.h> /* for _isnan */
+#endif
 #include <math.h>
 
 #include "access/htup_details.h"

src/backend/utils/adt/array_selfuncs.c

@@ -571,7 +571,7 @@ mcelem_array_contain_overlap_selec(Datum *mcelem, int nmcelem,
 	else
 	{
 		/* Without statistics make some default assumptions */
-		minfreq = 2 * DEFAULT_CONTAIN_SEL;
+		minfreq = 2 * (float4) DEFAULT_CONTAIN_SEL;
 	}
 
 	/* Decide whether it is faster to use binary search or not. */

src/interfaces/ecpg/ecpglib/typename.c

@@ -65,6 +65,7 @@ ecpg_type_name(enum ECPGttype typ)
 		default:
 			abort();
 	}
+	return ""; /* keep MSC compiler happy */
 }
 
 int