Fix #7693 muted error follow-up lines; Fix distinct records against $T/Record constraints

src/check_type.cpp

@@ -1865,6 +1865,11 @@ gb_internal SubstResult subst_unify_constraint(CheckerContext *c, Type *spec, Ty
 	if (is_type_untyped(tb)) {
 		r = subst_unify(c, spec, default_type(source), subst);
 	} else if (sb->kind == Type_Struct || sb->kind == Type_Union) {
+		if (tb == sb &&
+		    ((tb->kind == Type_Struct && tb->Struct.polymorphic_parent == nullptr) ||
+		     (tb->kind == Type_Union  && tb->Union.polymorphic_parent  == nullptr))) {
+			return Subst_Matched;
+		}
 		r = subst_unify(c, spec, source, subst); // record conformance keeps the Named types (match params)
 	} else {
 		r = subst_unify(c, sb, tb, subst);        // general: base-typed structural match

src/error.cpp

@@ -251,6 +251,10 @@ gb_internal void print_all_errors(void);
 typedef ERROR_OUT_PROC(ErrorOutProc);
 
 gb_internal ERROR_OUT_PROC(default_error_out_va) {
+	if (global_error_mute_depth > 0) {
+		// NOTE(bill): the error this would continue was muted, so there is no current error value
+		return;
+	}
 	char buf[4096] = {};
 	isize len = gb_snprintf_va(buf, gb_size_of(buf), fmt, va);
 	isize n = len-1;
@@ -765,10 +769,17 @@ gb_internal void warning_va(TokenPos const &pos, TokenPos end, char const *fmt,
 
 
 gb_internal void error_line_va(char const *fmt, va_list va) {
+	if (global_error_mute_depth > 0) {
+		return;
+	}
 	error_out_va(fmt, va);
 }
 
 gb_internal void error_no_newline_va(TokenPos const &pos, char const *fmt, va_list va) {
+	if (global_error_mute_depth > 0) {
+		global_error_mute_count += 1;
+		return;
+	}
 	global_error_collector.count.fetch_add(1);
 	mutex_lock(&global_error_collector.mutex);
 	if (global_error_collector.count.load() > MAX_ERROR_COLLECTOR_COUNT()) {