testsuite/C++: suppress filename canonicalization in module tests

The pathname underneath gcm.cache/ is determined from the effective name
used for the main input file of a particular module. When modules are
built, no canonicalization occurs for the main input file. Hence the
module file wouldn't be found if a different (the canonicalized) file
name was used when importing that same module. (This is an effect of
importing happening in the preprocessor, just like #include handling.)

Since it doesn't look easy to make module generation use libcpp's
maybe_shorter_path() (in fact I'd consider this a layering violation,
while cloning the logic would - at least in principle - be prone to both
going out of sync), simply suppress system header path canonicalization
for the respective tests.

gcc/testsuite/

	* g++.dg/modules/alias-1_b.C: Add -fno-canonical-system-headers.
	* g++.dg/modules/alias-1_d.C: Likewise.
	* g++.dg/modules/alias-1_e.C: Likewise.
	* g++.dg/modules/alias-1_f.C: Likewise.
	* g++.dg/modules/cpp-6_c.C: Likewise.
	* g++.dg/modules/dir-only-2_b.C: Likewise.

0 files changed, 0 insertions, 0 deletions