Removal of "or_else jump". Fixes to defer & macros/blocks, optimized failable return. @noscope macros removed. Disallow meaningless defer.

Correctly show error on return or rethrow inside of a defer. Fix copying an access expression. Removing scoped expr.

test/test_suite/defer/defer_and_expr_block.c3t

@@ -0,0 +1,40 @@
+// #target: x64-darwin
+module foo;
+extern fn void printf(char*,...);
+
+fn void main()
+{
+	defer printf("On exit\n");
+	{|
+		defer printf("Baz\n");
+		defer {|
+			defer printf("Hello!\n");
+			defer printf("1\n");
+			if (true) return 12;
+			defer printf("2\n");
+			return 34;
+		|};
+	|};
+	defer printf("On 2\n");
+}
+
+/* #expect: foo.ll
+
+define void @foo.main() #0 {
+entry:
+  %blockret = alloca i32, align 4
+  br label %if.then
+
+if.then:                                          ; preds = %entry
+  call void (i8*, ...) @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i32 0, i32 0))
+  call void (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.1, i32 0, i32 0))
+  store i32 12, i32* %blockret, align 4
+  br label %expr_block.exit
+
+expr_block.exit:                                  ; preds = %if.then
+  call void (i8*, ...) @printf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.5, i32 0, i32 0))
+  call void (i8*, ...) @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.6, i32 0, i32 0))
+  call void (i8*, ...) @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.7, i32 0, i32 0))
+  ret void
+}
+

test/test_suite/defer/defer_single_stmt.c3

@@ -0,0 +1,41 @@
+fn void test1()
+{
+	while (1) defer foo(); // #error: Looping over a raw 'defer'
+}
+
+fn void test1a()
+{
+	while (1) { defer foo(); }
+}
+
+fn void test2()
+{
+	if (1) defer foo(); // #error: An 'if' statement may not be followed by a raw 'defer'
+}
+
+fn void test2a()
+{
+	if (1) { defer foo(); }
+}
+
+fn void test3()
+{
+	defer defer foo(); // #error: A defer may not have a body consisting of a raw 'defer'
+}
+
+fn void test3a()
+{
+	defer { defer foo(); }
+}
+
+fn void test4()
+{
+	for (;;) defer foo(); // #error: Looping over a raw 'defer'
+}
+
+fn void test4a()
+{
+	for(;;) { defer foo(); }
+}
+
+fn void foo() {}

test/test_suite/defer/defer_with_rethrow.c3

@@ -0,0 +1,14 @@
+fn int! foo()
+{ return 1; }
+
+
+fn int! bar()
+{
+	defer {
+		{|
+			foo()?;
+		|};
+	}
+	defer foo()?; // #error: Returns are not allowed inside of defers.
+	return 1;
+}

test/test_suite/defer/defer_with_return.c3

@@ -0,0 +1,10 @@
+fn int! bar()
+{
+	defer {
+		{|
+			return 4;
+		|};
+	}
+	defer return 3; // #error: Return is not allowed inside of a defer
+	return 1;
+}