mh-mingw: Also set __USE_MINGW_ACCESS flag for C++ code.

From-SVN: r269784

config/ChangeLog

+2019-03-02  Johannes Pfau  <johannespfau@gmail.com>
+
+	* mh-mingw: Also set __USE_MINGW_ACCESS flag for C++ code.
+
 2018-10-31  Joseph Myers  <joseph@codesourcery.com>
 
 	PR bootstrap/82856

config/mh-mingw

@@ -2,6 +2,11 @@
 # Vista (see PR33281 for details).
 BOOT_CFLAGS += -D__USE_MINGW_ACCESS -Wno-pedantic-ms-format
 CFLAGS += -D__USE_MINGW_ACCESS
+STAGE1_CXXFLAGS += -D__USE_MINGW_ACCESS
+STAGE2_CXXFLAGS += -D__USE_MINGW_ACCESS
+STAGE3_CXXFLAGS += -D__USE_MINGW_ACCESS
+STAGE4_CXXFLAGS += -D__USE_MINGW_ACCESS
+
 # Increase stack limit to a figure based on the Linux default, with 4MB added
 # as GCC turns out to need that much more to pass all the limits-* tests.
 LDFLAGS += -Wl,--stack,12582912