Test the PSA alternative header configuration macros

Test that MBEDTLS_PSA_CRYPTO_PLATFORM_FILE and
MBEDTLS_PSA_CRYPTO_STRUCT_FILE can be set to files in a directory that comes
after the standard directory in the include file search path.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/Makefile b/tests/Makefile
index c9283c9..26947f4 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -219,6 +219,7 @@
 	rm -rf $(BINARIES) *.c *.datax
 	rm -f src/*.o src/drivers/*.o src/libmbed*
 	rm -f include/test/instrument_record_status.h
+	rm -f include/alt-extra/*/*_alt.h
 	rm -rf libtestdriver1
 	rm -f ../library/libtestdriver1.a
 else
@@ -244,6 +245,10 @@
 
 test: check
 
+# Generate variants of some headers for testing
+include/alt-extra/%_alt.h: ../include/%.h
+	perl -p -e 's/^(# *(define|ifndef) +\w+_)H\b/$${1}ALT_H/' $< >$@
+
 # Generate test library
 
 # Perl code that is executed to transform each original line from a library