[lldb] Fix build error from 07355c1c08

The error is: no matching function for call to 'transform(std::string&, std::__cxx11::basic_string<char>::iterator, <unresolved overloaded function type>)'

The fix: replace llvm::transform with an equally simple hand-rolled
loop.

lldb/source/Target/ABI.cpp

@@ -244,7 +244,8 @@ void MCBasedABI::AugmentRegisterInfo(RegisterInfo &info) {
 std::pair<uint32_t, uint32_t>
 MCBasedABI::GetEHAndDWARFNums(llvm::StringRef name) {
   std::string mc_name = GetMCName(name.str());
-  llvm::transform(mc_name, mc_name.begin(), std::toupper);
+  for (char &c : mc_name)
+    c = std::toupper(c);
   int eh = -1;
   int dwarf = -1;
   for (unsigned reg = 0; reg < m_mc_register_info_up->getNumRegs(); ++reg) {