[libunwind] Fix build error on 32 bit Arm after -Wcast-qual was added

[DavidSpickett]

Summary

New warning was added in https://reviews.llvm.org/D153911 which caused:
https://buildkite.com/llvm-project/libcxx-ci/builds/28407#01896b79-2a5e-4554-ac31-2abec5a8b281

../../libunwind/src/UnwindLevel1-gcc-ext.c:172:47: error: cast from 'const unsigned int *' to 'unsigned int *' drops const qualifier [-Werror,-Wcast-qual]

ex.pr_cache.ehtp = (_Unwind_EHT_Header *) unwindInfo;

I don't see any reason there should be a const here in the first place,
so just remove it.

[michaelplatings]

LGTM and fixes the issue for me. I agree there doesn't seem to be a good reason to have the const there in the first place.

[DavidSpickett]

clang-format

[MaskRay]

Looks great!

libunwind/src/UnwindLevel1-gcc-ext.c

 #else
     // Get the information for this frame.
     unw_proc_info_t frameInfo;
     if (__unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {
       return _URC_END_OF_STACK;
     }
 
     // Update the pr_cache in the mock exception object.
-    const uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
+    uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
     ex.pr_cache.fnstart = frameInfo.start_ip;
     ex.pr_cache.ehtp = (_Unwind_EHT_Header *) unwindInfo;
     ex.pr_cache.additional= frameInfo.flags;
 
     struct _Unwind_Context *context = (struct _Unwind_Context *)&cursor;
     // Get and call the personality function to unwind the frame.
     _Unwind_Personality_Fn handler = (_Unwind_Personality_Fn)frameInfo.handler;
     if (handler == NULL) {