fix catch handlers / match statements yielding past scope

compiler_tests.odin

@@ -2459,9 +2459,16 @@ bad_catch func() i32 {
 		_ = e
 	}
 }
+bad_nested_match func() i32 {
+	return fa() catch |e| {
+		match e {
+			.a: yield 3
+		}
+	}
+}
 main func() i32 {
 	_ = bad_error() catch 0
-	return bad_catch()
+	return bad_catch() + bad_nested_match()
 }
 `
 	source_file := source.Source{path="fallible_ergonomics.bro", text=text}
@@ -2478,12 +2485,15 @@ main func() i32 {
 
 	found_error := false
 	found_yield := false
+	found_misplaced_yield := false
 	for diagnostic in diagnostics.items {
 		found_error = found_error || strings.contains(diagnostic.message, "'try' error channel cannot be widened")
 		found_yield = found_yield || strings.contains(diagnostic.message, "a value block must end with an explicit 'yield'")
+		found_misplaced_yield = found_misplaced_yield || strings.contains(diagnostic.message, "'yield' is only valid as the final statement")
 	}
 	testing.expect(t, found_error)
 	testing.expect(t, found_yield)
+	testing.expect(t, found_misplaced_yield)
 
 	success_text := `A :: enum {
 	a
@@ -2540,10 +2550,11 @@ with_detail func(value i32) i32 ! DetailError {
 main func() i32 {
 	e DetailError = .code{3}
 	recovered :: with_detail(0) catch |err| {
-		match err {
-			.code |n|: yield n
-			.empty:    yield 9
+		result i32 :: match err {
+			.code |n|: n
+			.empty:    9
 		}
+		yield result
 	}
 	return accept(e) + accept(.code{4}) + accept(make_code(5)) + accept(.code{make_payload()}) + recovered - 24
 }
@@ -2617,17 +2628,19 @@ main func() i32 {
 	a :: accept(e)
 	b :: accept(.wrapped{line = 4, path = 3})
 	c :: with_payload(0) catch |err| {
-		match err {
-			.not_found |info|: yield info.path + info.line
-			.wrapped |info|:   yield info.path + info.line
-			.scalar |n|:       yield n
-			.empty:            yield 0
+		result i32 :: match err {
+			.not_found |info|: info.path + info.line
+			.wrapped |info|:   info.path + info.line
+			.scalar |n|:       n
+			.empty:            0
 		}
+		yield result
 	}
 	d :: inline_payload(0) catch |err| {
-		match err {
-			.inline_bad |info|: yield info.code + info.line
+		result i32 :: match err {
+			.inline_bad |info|: info.code + info.line
 		}
+		yield result
 	}
 	return a + b + c + d - 59
 }
@@ -2672,17 +2685,19 @@ inline_union func(value i32) i32 ! union(enum) {
 }
 main func() i32 {
 	a :: inline_enum(0) catch |e| {
-		if (e == .inline_bad) {
+		result i32 :: if (e == .inline_bad) {
 			yield 10
 		} else {
 			yield 11
 		}
+		yield result
 	}
 	b :: inline_union(0) catch |e| {
-		match e {
-			.inline_code |n|: yield n
-			.inline_empty:   yield 12
+		result i32 :: match e {
+			.inline_code |n|: n
+			.inline_empty:   12
 		}
+		yield result
 	}
 	return a + b - 16
 }