[lld] Use StringRef::consume_front_insensitive (NFC)

Author: kazutakahirata

lld/COFF/DriverUtils.cpp

@@ -310,13 +310,11 @@ void LinkerDriver::parseManifestUAC(StringRef arg) {
     arg = arg.ltrim();
     if (arg.empty())
       return;
-    if (arg.starts_with_insensitive("level=")) {
-      arg = arg.substr(strlen("level="));
+    if (arg.consume_front_insensitive("level=")) {
       std::tie(ctx.config.manifestLevel, arg) = arg.split(" ");
       continue;
     }
-    if (arg.starts_with_insensitive("uiaccess=")) {
-      arg = arg.substr(strlen("uiaccess="));
+    if (arg.consume_front_insensitive("uiaccess=")) {
       std::tie(ctx.config.manifestUIAccess, arg) = arg.split(" ");
       continue;
     }

lld/Common/Args.cpp

@@ -31,8 +31,8 @@ static int64_t getInteger(opt::InputArgList &args, unsigned key,
 
   int64_t v;
   StringRef s = a->getValue();
-  if (base == 16 && (s.starts_with("0x") || s.starts_with("0X")))
-    s = s.drop_front(2);
+  if (base == 16)
+    s.consume_front_insensitive("0x");
   if (to_integer(s, v, base))
     return v;
 

lld/MachO/Driver.cpp

@@ -952,8 +952,7 @@ static std::vector<SectionAlign> parseSectAlign(const opt::InputArgList &args) {
     StringRef segName = arg->getValue(0);
     StringRef sectName = arg->getValue(1);
     StringRef alignStr = arg->getValue(2);
-    if (alignStr.starts_with("0x") || alignStr.starts_with("0X"))
-      alignStr = alignStr.drop_front(2);
+    alignStr.consume_front_insensitive("0x");
     uint32_t align;
     if (alignStr.getAsInteger(16, align)) {
       error("-sectalign: failed to parse '" + StringRef(arg->getValue(2)) +