RFR: JDK-8080013 OpenJDK windows build fails due to warning in libfontmanager

[Magnus Ihse Bursie]

JDK-8074859, which turns on warnings-as-errors, unfortunately was not 
properly tested with open-only, just the Oracle closed build. An extra 
warning present in freetype2 code causes the build to fail.

Bug: https://bugs.openjdk.java.net/browse/JDK-8080013
WebRev inline:

diff --git a/make/lib/Awt2dLibraries.gmk b/make/lib/Awt2dLibraries.gmk
--- a/make/lib/Awt2dLibraries.gmk
+++ b/make/lib/Awt2dLibraries.gmk
@@ -653,7 +653,7 @@
      DISABLED_WARNINGS_clang := unused-value incompatible-pointer-types \
          tautological-constant-out-of-range-compare int-to-pointer-cast, \
      DISABLED_WARNINGS_solstudio := truncwarn, \
-    DISABLED_WARNINGS_microsoft := 4267 4244 4018 4090 4996, \
+    DISABLED_WARNINGS_microsoft := 4267 4244 4018 4090 4996 4146, \
      WARNINGS_AS_ERRORS_gcc := false, \
      WARNINGS_AS_ERRORS_solstudio := false, \
      MAPFILE := $(BUILD_LIBFONTMANAGER_MAPFILE), \

/Magnus