--- gcc/Makefile.in.orig	2022-11-02 20:13:34 UTC
+++ gcc/Makefile.in
@@ -630,6 +630,8 @@ libsubdir = $(libdir)/gcc/$(real_target_noncanonical)/
 
 # Directory in which the compiler finds libraries etc.
 libsubdir = $(libdir)/gcc/$(real_target_noncanonical)/$(version)$(accel_dir_suffix)
+# Directory in which the compiler finds headers.
+libsubincludedir = $(libdir)/gcc/$(target_alias)/$(version)/include
 # Directory in which the compiler finds executables
 libexecsubdir = $(libexecdir)/gcc/$(real_target_noncanonical)/$(version)$(accel_dir_suffix)
 # Directory in which all plugin resources are installed
@@ -3609,6 +3611,7 @@ installdirs:
 # $(libdir)/gcc/include isn't currently searched by cpp.
 installdirs:
 	$(mkinstalldirs) $(DESTDIR)$(libsubdir)
+	$(mkinstalldirs) $(DESTDIR)$(libsubincludedir)
 	$(mkinstalldirs) $(DESTDIR)$(libexecsubdir)
 	$(mkinstalldirs) $(DESTDIR)$(bindir)
 	$(mkinstalldirs) $(DESTDIR)$(includedir)