Add a target environment for CoreCLR.

Although targeting CoreCLR is similar to targeting MSVC, there are
certain important differences that the backend must be aware of
(e.g. differences in stack probes, EH, and library calls).

Differential Revision: http://reviews.llvm.org/D11012

llvm-svn: 245115
diff --git a/llvm/test/CodeGen/X86/stack-probe-size.ll b/llvm/test/CodeGen/X86/stack-probe-size.ll
index 21482c3..43c62c1 100644
--- a/llvm/test/CodeGen/X86/stack-probe-size.ll
+++ b/llvm/test/CodeGen/X86/stack-probe-size.ll
@@ -6,10 +6,10 @@
 ; stack probe size equals the page size (4096 bytes for all x86 targets), and
 ; this is unlikely to change in the future.
 ;
-; RUN: llc < %s | FileCheck %s
+; RUN: llc -mtriple=i686-windows-msvc < %s | FileCheck %s
+; RUN: llc -mtriple=i686-windows-coreclr < %s | FileCheck %s
 
 target datalayout = "e-m:w-p:32:32-i64:64-f80:32-n8:16:32-S32"
-target triple = "i686-pc-windows-msvc"
 
 define i32 @test1() "stack-probe-size"="0" {
   %buffer = alloca [4095 x i8]