Bug 142575: use the PRIVATE keyword for the /EXPORT linker option.

security/nss/lib/nss/config.mk

@@ -99,8 +99,8 @@ MKSHLIB += -R '$$ORIGIN'
 endif
 
 ifeq (,$(filter-out WINNT WIN95,$(OS_TARGET)))
-# Export 'mktemp' to be backward compatible with NSS 3.2.x and 3.3.x.
-# See bug 142575.
+# Export 'mktemp' to be backward compatible with NSS 3.2.x and 3.3.x
+# but do not put it in the import library.  See bug 142575.
 DEFINES += -DWIN32_NSS3_DLL_COMPAT
-DLLFLAGS += -EXPORT:mktemp=nss_mktemp
+DLLFLAGS += -EXPORT:mktemp=nss_mktemp,PRIVATE
 endif