X86 is the only target that uses coff format. This should fixes test failures running on Windows, Cygwin, or MingW hosts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135639 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index 0b0a3e0..0cf98bd 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -518,8 +518,9 @@
       (T.isOSDarwin() || T.getEnvironment() == Triple::MachO)) {
     Env = IsMachO;
     InitMachOMCObjectFileInfo(T);
-  } else if (T.getOS() == Triple::MinGW32 || T.getOS() == Triple::Cygwin ||
-             T.getOS() == Triple::Win32) {
+  } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
+             (T.getOS() == Triple::MinGW32 || T.getOS() == Triple::Cygwin ||
+              T.getOS() == Triple::Win32)) {
     Env = IsCOFF;
     InitCOFFMCObjectFileInfo(T);
   } else {