TAGS: Fix lookup in test/suites/!(test_suite_*).function

tests/suites/helpers.function and tests/suites/*_test.function contain
"#line" directives. This causes the TAGS file to contain references
pointing to the file path named in the "#line" directives, which is
relative to the "tests" directory rather than to the toplevel. Fix
this by telling etags to ignore "#line" directives, which is ok since
we aren't actually running it on any generated code.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/Makefile b/Makefile
index 3942fbd..ffa3aa0 100644
--- a/Makefile
+++ b/Makefile
@@ -124,11 +124,11 @@
 ## Editor navigation files
 C_SOURCE_FILES = $(wildcard include/*/*.h library/*.[hc] programs/*/*.[hc] tests/suites/*.function)
 # Exuberant-ctags invocation. Other ctags implementations may require different options.
-CTAGS = ctags --langmap=c:+.h.function -o
+CTAGS = ctags --langmap=c:+.h.function --line-directives=no -o
 tags: $(C_SOURCE_FILES)
 	$(CTAGS) $@ $(C_SOURCE_FILES)
 TAGS: $(C_SOURCE_FILES)
-	etags -o $@ $(C_SOURCE_FILES)
+	etags --no-line-directive -o $@ $(C_SOURCE_FILES)
 global: GPATH GRTAGS GSYMS GTAGS
 GPATH GRTAGS GSYMS GTAGS: $(C_SOURCE_FILES)
 	ls $(C_SOURCE_FILES) | gtags -f - --gtagsconf .globalrc