[Mips] Avoid repeated map lookups (NFC) (#110075)

Author: kazutakahirata

llvm/lib/Target/Mips/MipsAsmPrinter.cpp

@@ -81,12 +81,8 @@ bool MipsAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 
   MipsFI = MF.getInfo<MipsFunctionInfo>();
   if (Subtarget->inMips16Mode())
-    for (const auto &I : MipsFI->StubsNeeded) {
-      const char *Symbol = I.first;
-      const Mips16HardFloatInfo::FuncSignature *Signature = I.second;
-      if (StubsNeeded.find(Symbol) == StubsNeeded.end())
-        StubsNeeded[Symbol] = Signature;
-    }
+    for (const auto &I : MipsFI->StubsNeeded)
+      StubsNeeded.insert(I);
   MCP = MF.getConstantPool();
 
   // In NaCl, all indirect jump targets must be aligned to bundle size.