[3.7] bpo-32931: fix macOS 10.9+ installer c++ compiler name (GH-5856)

(cherry picked from commit acd7163c0a0674b2fb6cc0178d52cf90c953fbae)

Co-authored-by: Ned Deily <nad@python.org>
diff --git a/Mac/BuildScript/build-installer.py b/Mac/BuildScript/build-installer.py
index 1a7080c..bacdbfb 100755
--- a/Mac/BuildScript/build-installer.py
+++ b/Mac/BuildScript/build-installer.py
@@ -161,7 +161,7 @@
         '10.5': ('gcc', 'g++'),
         '10.6': ('gcc', 'g++'),
     }
-    return target_cc_map.get(DEPTARGET, ('gcc', 'gcc++') )
+    return target_cc_map.get(DEPTARGET, ('gcc', 'g++') )
 
 CC, CXX = getTargetCompilers()