fix: align __cxa_throw mprotect ranges

[supervacuus]

📜 Description

Page aligns Mach-O (down for start and up for end) section offsets before using them as address and size arguments with mprotect().

Also checked against KSCrash

• 2.5.1 (latest stable) still uses unaligned addresses.
• develop: severely changed the swapper implementation altogether and already uses page-aligned addresses.

Ergo: no need to align with upstream. We replace it with develop anyway (no need to introduce surrounding changes to fix this).

💡 Motivation and Context

Fixes #8156

mprotect() has always required page-aligned addresses, but only in xOS/Xcode 27 does it return EINVAL for unaligned addresses.

💚 How did you test it?

• built with Xcode 27 beta and ran tests on iOS 27 simulator
• verified that unaligned addresses failed and that aligned addresses successfully added protection on iOS 27 simulator
• ran the iOS test suite against iOS 18.4 to counter-check

📝 Checklist

You have to check all boxes before merging:

• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.
• If I added a new public API, I also added it to the SentryObjC wrapper.

[sentry]

📲 Install Builds

iOS

🔗 App Name	App ID	Version	Configuration
SDK-Size	io.sentry.sample.SDK-Size	9.19.0 (1)	Release

⚙️ sentry-cocoa Build Distribution Settings

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1210.27 ms	1244.69 ms	34.42 ms
Size	24.14 KiB	1.22 MiB	1.20 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
9787f05	1233.67 ms	1269.00 ms	35.33 ms
119dc37	1217.64 ms	1250.44 ms	32.80 ms
31a83fd	1218.63 ms	1247.18 ms	28.55 ms
5cc1f4e	1223.49 ms	1258.69 ms	35.20 ms
92bcc8f	1233.43 ms	1270.20 ms	36.77 ms
943b250	1214.69 ms	1257.32 ms	42.63 ms
78aad96	1232.02 ms	1262.42 ms	30.40 ms
1caa212	1229.06 ms	1251.23 ms	22.17 ms
2446b3d	1218.36 ms	1253.98 ms	35.62 ms
6844d69	1228.25 ms	1265.20 ms	36.95 ms

App size

Revision	Plain	With Sentry	Diff
9787f05	24.14 KiB	1.18 MiB	1.15 MiB
119dc37	24.14 KiB	1.16 MiB	1.13 MiB
31a83fd	24.14 KiB	1.17 MiB	1.15 MiB
5cc1f4e	24.14 KiB	1.18 MiB	1.16 MiB
92bcc8f	24.14 KiB	1.15 MiB	1.13 MiB
943b250	24.14 KiB	1.17 MiB	1.15 MiB
78aad96	24.14 KiB	1.18 MiB	1.16 MiB
1caa212	24.14 KiB	1.18 MiB	1.16 MiB
2446b3d	24.14 KiB	1.17 MiB	1.15 MiB
6844d69	24.14 KiB	1.20 MiB	1.17 MiB

Previous results on branch: supervacuus/fix/page_align_addresses_for_mprotect

Startup times

Revision	Plain	With Sentry	Diff
3f2d039	1222.11 ms	1258.05 ms	35.93 ms

App size

Revision	Plain	With Sentry	Diff
3f2d039	24.14 KiB	1.22 MiB	1.20 MiB