[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/src/DwarfInstructions.hpp b/src/DwarfInstructions.hpp
index cee4ea5..77f1383 100644
--- a/src/DwarfInstructions.hpp
+++ b/src/DwarfInstructions.hpp
@@ -25,7 +25,7 @@
 namespace libunwind {
 
 
-/// DwarfInstructions maps abtract DWARF unwind instructions to a particular
+/// DwarfInstructions maps abstract DWARF unwind instructions to a particular
 /// architecture
 template <typename A, typename R>
 class DwarfInstructions {
@@ -241,7 +241,7 @@
             return UNW_EBADREG;
         } else if (i == (int)cieInfo.returnAddressRegister) {
             // Leaf function keeps the return address in register and there is no
-            // explicit intructions how to restore it.
+            // explicit instructions how to restore it.
             returnAddress = registers.getRegister(cieInfo.returnAddressRegister);
         }
       }
@@ -331,7 +331,7 @@
 #endif
 
       // Return address is address after call site instruction, so setting IP to
-      // that does simualates a return.
+      // that does simulates a return.
       newRegisters.setIP(returnAddress);
 
       // Simulate the step by replacing the register set with the new ones.
@@ -635,7 +635,7 @@
       svalue = (sint_t)*sp;
       *sp = (pint_t)(svalue >> value);
       if (log)
-        fprintf(stderr, "shift left arithmetric\n");
+        fprintf(stderr, "shift left arithmetic\n");
       break;
 
     case DW_OP_xor: