[libunwind] Fixed an upcoming clang -Wsign-conversion warning

[fahadnayyar]

Summary

Fixing an upcoming clang warning (from https://reviews.llvm.org/D139114) in libunwind.

[MaskRay]

Thanks!

[housel]

libunwind/src/AddressSpace.hpp

263

[MaskRay]

libunwind/src/AddressSpace.hpp

263

return (int64_t)result; (delete space)

[fahadnayyar]

Removed space.

[fahadnayyar]

Correction.

[MaskRay]

LGTM.

libunwind/src/AddressSpace.hpp

inline uint64_t LocalAddressSpace::getULEB128(pint_t &addr, pint_t end) {
   addr = (pint_t) p;
   return result;
 }
 
 /// Read a SLEB128 into a 64-bit word.
 inline int64_t LocalAddressSpace::getSLEB128(pint_t &addr, pint_t end) {
   const uint8_t *p = (uint8_t *)addr;
   const uint8_t *pend = (uint8_t *)end;
-  int64_t result = 0;
+  uint64_t result = 0;
   int bit = 0;
   uint8_t byte;
   do {
     if (p == pend)
       _LIBUNWIND_ABORT("truncated sleb128 expression");
     byte = *p++;
     result |= (uint64_t)(byte & 0x7f) << bit;
     bit += 7;
   } while (byte & 0x80);
   // sign extend negative numbers
   if ((byte & 0x40) != 0 && bit < 64)
     result |= (-1ULL) << bit;
   addr = (pint_t) p;
-  return result;
+  return (int64_t)result;
 }
 
 inline LocalAddressSpace::pint_t
 LocalAddressSpace::getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
                                pint_t datarelBase) {
   pint_t startAddr = addr;
   const uint8_t *p = (uint8_t *)addr;
   pint_t result;