ARM-Darwin: Use the *-*-darwin-eabi triple for v6m & v7m archs

These arch arguments are used for embedded targets (obviously) which need a
different calling convention to iOS.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193328 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 843cc1b..4deaa64 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -149,7 +149,9 @@
     Str[4] = '0' + (Rev % 10);
     Str[5] = '\0';
     Builder.defineMacro("__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__", Str);
-  } else {
+  } else if (Triple.getArchName() != "thumbv6m" &&
+             Triple.getArchName() != "thumbv7m" &&
+             Triple.getArchName() != "thumbv7em") {
     // Note that the Driver allows versions which aren't representable in the
     // define (because we only get a single digit for the minor and micro
     // revision numbers). So, we limit them to the maximum representable