[qfcc] Add failing test for array life

It seems that the optimizer keeps array assignments live when passing
the array as a pointer, but not when passing the address of an element.
Found when testing the following code:

    BasisBlade *pga_blades[16] = {
        blades[1],  blades[2],  blades[3],  blades[4],
        blades[7],  blades[6],  blades[5],  blades[0],
        blades[8],  blades[9],  blades[10], blades[15],
        blades[14], blades[13], blades[12], blades[11],
    };
    BasisGroup *pga_groups[4] = {
        [BasisGroup new:4 basis:&pga_blades[ 0]],
        [BasisGroup new:4 basis:&pga_blades[ 4]],
        [BasisGroup new:4 basis:&pga_blades[ 8]],
        [BasisGroup new:4 basis:&pga_blades[12]],
    };

Only the first element of pga_blades is being assigned in the optimized
code, but everything is correct when not optimizing.

tools/qfcc/test/Makemodule.am

@@ -10,6 +10,7 @@ fail_bins=
 test_progs_dat=\
 	tools/qfcc/test/address-cast.dat \
 	tools/qfcc/test/alignment.dat \
+	tools/qfcc/test/arraylife.dat \
 	tools/qfcc/test/assignchain.dat \
 	tools/qfcc/test/anonstruct.dat \
 	tools/qfcc/test/chewed-alias.dat \
@@ -157,6 +158,16 @@ tools/qfcc/test/anonstruct.run: $(qfcc_test_run_deps)
 include $(anonstruct_dep) # am--include-marker
 r_depfiles_remade += $(anonstruct_dep)
 
+tools_qfcc_test_arraylife_dat_SOURCES=tools/qfcc/test/arraylife.r
+arraylife_obj=$(tools_qfcc_test_arraylife_dat_SOURCES:.r=.o)
+arraylife_dep=$(call qcautodep,$(tools_qfcc_test_arraylife_dat_SOURCES))
+tools/qfcc/test/arraylife.dat$(EXEEXT): $(arraylife_obj) $(QFCC_DEP)
+	$(V_QFCCLD)$(QLINK) -o $@ $(arraylife_obj)
+tools/qfcc/test/arraylife.run: $(qfcc_test_run_deps)
+	@$(top_srcdir)/tools/qfcc/test/build-run $@
+include $(arraylife_dep) # am--include-marker
+r_depfiles_remade += $(arraylife_dep)
+
 tools_qfcc_test_assignchain_dat_SOURCES=tools/qfcc/test/assignchain.r
 assignchain_obj=$(tools_qfcc_test_assignchain_dat_SOURCES:.r=.o)
 assignchain_dep=$(call qcautodep,$(tools_qfcc_test_assignchain_dat_SOURCES))

tools/qfcc/test/arraylife.r

@@ -0,0 +1,20 @@
+vector
+bar (float *v)
+{
+	return [v[0], v[1], v[2]];
+}
+
+vector
+foo (float x, float y, float z)
+{
+	float v[3] = { x, y, z };
+	return bar (&v[0]);
+}
+
+int
+main ()
+{
+	int ret = 0;
+	ret |= foo(1,2,3) != [1, 2, 3];
+	return ret;
+}