enforce leading comptime params

compiler_tests.odin

@@ -2650,6 +2650,42 @@ main func() void {
 	testing.expect(t, unrecoverable >= 3)
 }
 
+@(test)
+comptime_params_must_form_leading_prefix :: proc(t: ^testing.T) {
+	text := `valid func($T type, $N usize, value T) [N]T {
+	result [N]T = undefined
+	_ = value
+	return result
+}
+runtime_first func(value i32, $T type, $N usize) T { return value }
+split func($T type, value T, $N usize) [N]T {
+	result [N]T = undefined
+	_ = value
+	return result
+}
+main func() void {}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	count := 0
+	for diagnostic in diagnostics.items {
+		if strings.contains(diagnostic.message, "comptime parameters must form a leading parameter prefix") {
+			count += 1
+		}
+	}
+	testing.expect_value(t, count, 2)
+}
+
 @(test)
 comptime_type_params_specialize_by_type_and_omit_runtime_args :: proc(t: ^testing.T) {
 	text := `Point :: struct {