[mips] Recognise the triple used by Debian for MIPS n32 ABI

Triples like mips64-linux-gnuabin32 are documented in this article:
https://wiki.debian.org/Multiarch/Tuples

llvm-svn: 313231
diff --git a/llvm/unittests/ADT/TripleTest.cpp b/llvm/unittests/ADT/TripleTest.cpp
index 0cedbd5..db11f42 100644
--- a/llvm/unittests/ADT/TripleTest.cpp
+++ b/llvm/unittests/ADT/TripleTest.cpp
@@ -332,6 +332,12 @@
   EXPECT_EQ(Triple::Linux, T.getOS());
   EXPECT_EQ(Triple::GNU, T.getEnvironment());
 
+  T = Triple("mips64el-img-linux-gnuabin32");
+  EXPECT_EQ(Triple::mips64el, T.getArch());
+  EXPECT_EQ(Triple::ImaginationTechnologies, T.getVendor());
+  EXPECT_EQ(Triple::Linux, T.getOS());
+  EXPECT_EQ(Triple::GNUABIN32, T.getEnvironment());
+
   T = Triple("mips64el-unknown-linux-gnuabi64");
   EXPECT_EQ(Triple::mips64el, T.getArch());
   EXPECT_EQ(Triple::UnknownVendor, T.getVendor());