[libunwind] Fixed a number of typos

I went over the output of the following mess of a command:

`(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z | parallel --xargs -0 cat | aspell list --mode=none --ignore-case | grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n | grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)`

and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).

Reviewed By: #libunwind, MaskRay

Differential Revision: https://reviews.llvm.org/D130948

NOKEYCHECK=True
GitOrigin-RevId: dad00daa7a0a656640f7579c2c21933ef97a1978
diff --git a/test/unwind_leaffunction.pass.cpp b/test/unwind_leaffunction.pass.cpp
index 31c2254..bdeb44a 100644
--- a/test/unwind_leaffunction.pass.cpp
+++ b/test/unwind_leaffunction.pass.cpp
@@ -28,7 +28,8 @@
   (void)arg;
   Dl_info info = { 0, 0, 0, 0 };
 
-  // Unwind util the main is reached, above frames deeped on the platfrom and architecture.
+  // Unwind until the main is reached, above frames deeped on the platform and
+  // architecture.
   if (dladdr(reinterpret_cast<void *>(_Unwind_GetIP(ctx)), &info) &&
       info.dli_sname && !strcmp("main", info.dli_sname)) {
     _Exit(0);