[clang] [MinGW] Link kernel32 once after the last instance of msvcrt

The msvcrt library isn't a pure import library; it does contain
regular object files with wrappers/fallbacks, and these can require
linking against kernel32.

This only makes a difference when linking with ld.bfd, as lld
always searches all static libraries.

This matches a similar change made recently in gcc in
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=850533ab160ef40eccfd039e1e3b138cf26e76b8,
although clang adds --start-group --end-group around these libraries
if -static is specified, which gcc doesn't. But try to match gcc's
linking order in any case, for consistency.

Differential Revision: https://reviews.llvm.org/D80880

clang/lib/Driver/ToolChains/MinGW.cpp

@@ -304,10 +304,13 @@ void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA,
         CmdArgs.push_back("-lkernel32");
       }
 
-      if (Args.hasArg(options::OPT_static))
+      if (Args.hasArg(options::OPT_static)) {
         CmdArgs.push_back("--end-group");
-      else
+      } else {
         AddLibGCC(Args, CmdArgs);
+        if (!HasWindowsApp)
+          CmdArgs.push_back("-lkernel32");
+      }
     }
 
     if (!Args.hasArg(options::OPT_nostartfiles)) {

clang/test/Driver/mingw-msvcrt.c

@@ -4,6 +4,7 @@
 // RUN: %clang -v -target i686-pc-windows-gnu -lucrt -### %s 2>&1 | FileCheck -check-prefix=CHECK_UCRT %s
 
 // CHECK_DEFAULT: "-lmingwex" "-lmsvcrt" "-ladvapi32"
+// CHECK_DEFAULT-SAME: "-lmsvcrt" "-lkernel32" "{{.*}}crtend.o"
 // CHECK_MSVCR120: "-lmsvcr120"
 // CHECK_MSVCR120-SAME: "-lmingwex" "-ladvapi32"
 // CHECK_UCRTBASE: "-lucrtbase"