[clang] [MinGW] Recognize -lcrtdll as a library replacing -lmsvcrt

[rnk]

lgtm

clang/lib/Driver/ToolChains/MinGW.cpp

if (RLT == ToolChain::RLT_Libgcc) {
     }
   } else {
     AddRunTimeLibs(getToolChain(), getToolChain().getDriver(), CmdArgs, Args);
   }
 
   CmdArgs.push_back("-lmoldname");
   CmdArgs.push_back("-lmingwex");
   for (auto Lib : Args.getAllArgValues(options::OPT_l))
-    if (StringRef(Lib).startswith("msvcr") || StringRef(Lib).startswith("ucrt"))
+    if (StringRef(Lib).startswith("msvcr") ||
+        StringRef(Lib).startswith("ucrt") ||
+        StringRef(Lib).startswith("crtdll"))
       return;
   CmdArgs.push_back("-lmsvcrt");
 }
 
 void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                         const InputInfo &Output,
                                         const InputInfoList &Inputs,
                                         const ArgList &Args,

clang/test/Driver/mingw-msvcrt.c

 // RUN: %clang -v -target i686-pc-windows-gnu -### %s 2>&1 | FileCheck -check-prefix=CHECK_DEFAULT %s
 // RUN: %clang -v -target i686-pc-windows-gnu -lmsvcr120 -### %s 2>&1 | FileCheck -check-prefix=CHECK_MSVCR120 %s
 // RUN: %clang -v -target i686-pc-windows-gnu -lucrtbase -### %s 2>&1 | FileCheck -check-prefix=CHECK_UCRTBASE %s
 // RUN: %clang -v -target i686-pc-windows-gnu -lucrt -### %s 2>&1 | FileCheck -check-prefix=CHECK_UCRT %s
+// RUN: %clang -v -target i686-pc-windows-gnu -lcrtdll -### %s 2>&1 | FileCheck -check-prefix=CHECK_CRTDLL %s
 
 // CHECK_DEFAULT: "-lmingwex" "-lmsvcrt" "-ladvapi32"
 // CHECK_DEFAULT-SAME: "-lmsvcrt" "-lkernel32" "{{.*}}crtend.o"
 // CHECK_MSVCR120: "-lmsvcr120"
 // CHECK_MSVCR120-SAME: "-lmingwex" "-ladvapi32"
 // CHECK_UCRTBASE: "-lucrtbase"
 // CHECK_UCRTBASE-SAME: "-lmingwex" "-ladvapi32"
 // CHECK_UCRT: "-lucrt"
 // CHECK_UCRT-SAME: "-lmingwex" "-ladvapi32"
+// CHECK_CRTDLL: "-lcrtdll"
+// CHECK_CRTDLL-SAME: "-lmingwex" "-ladvapi32"