Makefile: generate the VC 14.20 project files at dist-time

Follow-up to 28287092cc (#12282)

Closes #12290

Makefile.am

@@ -277,6 +277,7 @@ checksrc:
 
 vc-ide: $(VC14_LIBVCXPROJ_DEPS) $(VC14_SRCVCXPROJ_DEPS) \
  $(VC14_10_LIBVCXPROJ_DEPS) $(VC14_10_SRCVCXPROJ_DEPS)  \
+ $(VC14_20_LIBVCXPROJ_DEPS) $(VC14_20_SRCVCXPROJ_DEPS)  \
  $(VC14_30_LIBVCXPROJ_DEPS) $(VC14_30_SRCVCXPROJ_DEPS)
 	@(win32_lib_srcs='$(LIB_CFILES)'; \
 	win32_lib_hdrs='$(LIB_HFILES) config-win32.h'; \
@@ -486,6 +487,29 @@ function gen_element(type, dir, file)\
 		-v src_x_hdrs="$$sorted_src_x_hdrs" \
 		"$$awk_code" $(srcdir)/$(VC14_10_SRCTMPL) > $(VC14_10_SRCVCXPROJ) || { exit 1; }; \
 	\
+	echo "generating '$(VC14_20_LIBVCXPROJ)'"; \
+	awk -v proj_type=vcxproj \
+		-v lib_srcs="$$sorted_lib_srcs" \
+		-v lib_hdrs="$$sorted_lib_hdrs" \
+		-v lib_rc="$$win32_lib_rc" \
+		-v lib_vauth_srcs="$$sorted_lib_vauth_srcs" \
+		-v lib_vauth_hdrs="$$sorted_lib_vauth_hdrs" \
+		-v lib_vquic_srcs="$$sorted_lib_vquic_srcs" \
+		-v lib_vquic_hdrs="$$sorted_lib_vquic_hdrs" \
+		-v lib_vssh_srcs="$$sorted_lib_vssh_srcs" \
+		-v lib_vssh_hdrs="$$sorted_lib_vssh_hdrs" \
+		-v lib_vtls_srcs="$$sorted_lib_vtls_srcs" \
+		-v lib_vtls_hdrs="$$sorted_lib_vtls_hdrs" \
+		"$$awk_code" $(srcdir)/$(VC14_20_LIBTMPL) > $(VC14_20_LIBVCXPROJ) || { exit 1; }; \
+	\
+	echo "generating '$(VC14_20_SRCVCXPROJ)'"; \
+	awk -v proj_type=vcxproj \
+		-v src_srcs="$$sorted_src_srcs" \
+		-v src_hdrs="$$sorted_src_hdrs" \
+		-v src_rc="$$win32_src_rc" \
+		-v src_x_srcs="$$sorted_src_x_srcs" \
+		-v src_x_hdrs="$$sorted_src_x_hdrs" \
+		"$$awk_code" $(srcdir)/$(VC14_20_SRCTMPL) > $(VC14_20_SRCVCXPROJ) || { exit 1; };) \
 	echo "generating '$(VC14_30_LIBVCXPROJ)'"; \
 	awk -v proj_type=vcxproj \
 		-v lib_srcs="$$sorted_lib_srcs" \