[DebugInfo] Use StringRef::consume_front (NFC)

Author: kazutakahirata

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

@@ -181,8 +181,7 @@ DWARFTypePrinter::appendUnqualifiedNameBefore(DWARFDie D,
     Word = true;
     StringRef Name = NamePtr;
     static constexpr StringRef MangledPrefix = "_STN|";
-    if (Name.starts_with(MangledPrefix)) {
-      Name = Name.drop_front(MangledPrefix.size());
+    if (Name.consume_front(MangledPrefix)) {
       auto Separator = Name.find('|');
       assert(Separator != StringRef::npos);
       StringRef BaseName = Name.substr(0, Separator);

llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp

@@ -210,8 +210,8 @@ Error SymbolizableObjectFile::addSymbol(const SymbolRef &Symbol,
       SymbolAddress = OpdExtractor->getAddress(&OpdOffset);
   }
   // Mach-O symbol table names have leading underscore, skip it.
-  if (Module->isMachO() && !SymbolName.empty() && SymbolName[0] == '_')
-    SymbolName = SymbolName.drop_front();
+  if (Module->isMachO())
+    SymbolName.consume_front("_");
 
   if (Obj.isELF() && ELFSymbolRef(Symbol).getBinding() != ELF::STB_LOCAL)
     ELFSymIdx = 0;