[gcc r10-10342] mh-mingw: Set __USE_MINGW_ACCESS in missed C++ flags variables

[Martin Liska]

https://gcc.gnu.org/g:9f84f267b166137317f140eae4508b87b20ec485

commit r10-10342-g9f84f267b166137317f140eae4508b87b20ec485
Author: Martin Storsjö <martin@martin.st>
Date:   Fri Apr 9 14:46:36 2021 +0300

    mh-mingw: Set __USE_MINGW_ACCESS in missed C++ flags variables
    
    This is similar to what was done in
    eea4e2ff0a3f5e7f37df204c070cc5d9ef339e6e (where it was added to
    STAGE*_CXXFLAGS), but this adds the flag to the CXXFLAGS and
    BOOT_CXXFLAGS variables too (as it's already added to CFLAGS and
    BOOT_CFLAGS).
    
    2021-04-09  Martin Storsjö  <martin@martin.st>
    
    config/ChangeLog:
            * mh-mingw: Set __USE_MINGW_ACCESS in missed C++ flags
            variables
    
    (cherry picked from commit 89e95ad2e7679322b2f5ee9070ff2721d5ca1d6d)

Diff:
---
 config/mh-mingw | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/config/mh-mingw b/config/mh-mingw
index a795096f038..e91367a7112 100644
--- a/config/mh-mingw
+++ b/config/mh-mingw
@@ -1,7 +1,9 @@
 # Add -D__USE_MINGW_ACCESS to enable the built compiler to work on Windows
 # Vista (see PR33281 for details).
 BOOT_CFLAGS += -D__USE_MINGW_ACCESS -Wno-pedantic-ms-format
+BOOT_CXXFLAGS += -D__USE_MINGW_ACCESS -Wno-pedantic-ms-format
 CFLAGS += -D__USE_MINGW_ACCESS
+CXXFLAGS += -D__USE_MINGW_ACCESS
 STAGE1_CXXFLAGS += -D__USE_MINGW_ACCESS
 STAGE2_CXXFLAGS += -D__USE_MINGW_ACCESS
 STAGE3_CXXFLAGS += -D__USE_MINGW_ACCESS