[qfcc] Properly dup symbol for declaration

The unification of qc and c function symbol handling made it important
that the new symbol was a proper duplicate (minus being in a table) of
the old symbol. This fixes redeclared prototypes (especially for
qc-style functions, not encountered for c-style). Complete with unit
test :)

tools/qfcc/source/symtab.c

@@ -260,6 +260,8 @@ declare_symbol (specifier_t spec, const expr_t *init, symtab_t *symtab)
 		// due to the way declarations work, we need a new symbol at all times.
 		// redelcarations will be checked later
 		s = new_symbol (s->name);
+		*s = *spec.sym;
+		s->table = nullptr;
 	}
 
 	if (!spec.type_expr && !spec.is_function) {

tools/qfcc/test/Makemodule.am

@@ -57,6 +57,7 @@ test_progs_dat=\
 	tools/qfcc/test/motor-point.dat \
 	tools/qfcc/test/motor-xform.dat \
 	tools/qfcc/test/quaternion.dat \
+	tools/qfcc/test/reproto.dat \
 	tools/qfcc/test/return-ivar.dat \
 	tools/qfcc/test/return-postop.dat \
 	tools/qfcc/test/sendv.dat \
@@ -692,6 +693,16 @@ tools/qfcc/test/quaternion.run: $(qfcc_test_run_deps)
 include $(quaternion_dep) # am--include-marker
 r_depfiles_remade += $(quaternion_dep)
 
+tools_qfcc_test_reproto_dat_SOURCES=tools/qfcc/test/reproto.r
+reproto_obj=$(tools_qfcc_test_reproto_dat_SOURCES:.r=.o)
+reproto_dep=$(call qcautodep,$(tools_qfcc_test_reproto_dat_SOURCES))
+tools/qfcc/test/reproto.dat$(EXEEXT): $(reproto_obj) $(QFCC_DEP)
+	$(V_QFCCLD)$(QLINK) -o $@ $(reproto_obj)
+tools/qfcc/test/reproto.run: $(qfcc_test_run_deps)
+	@$(top_srcdir)/tools/qfcc/test/build-run $@
+include $(reproto_dep) # am--include-marker
+r_depfiles_remade += $(reproto_dep)
+
 tools_qfcc_test_return_ivar_dat_SOURCES=tools/qfcc/test/return-ivar.r
 return_ivar_obj=$(tools_qfcc_test_return_ivar_dat_SOURCES:.r=.o)
 return_ivar_dep=$(call qcautodep,$(tools_qfcc_test_return_ivar_dat_SOURCES))

tools/qfcc/test/reproto.r

@@ -0,0 +1,8 @@
+float (entity targ) visible;
+float (entity targ) visible;
+
+int
+main (void)
+{
+	return 0;	// to survive and prevail :)
+}