autoconf: Re-introduce LLVM_HOSTTRIPLE since r143500, as rework of PR11060.

cmake: Add LLVM_HOSTTRIPLE. For now, it is same as TARGET_TRIPLE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160609 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/configure b/configure
index 72145bc..fcd9179 100755
--- a/configure
+++ b/configure
@@ -20949,6 +20949,11 @@
 
 
 cat >>confdefs.h <<_ACEOF
+#define LLVM_HOSTTRIPLE "$host"
+_ACEOF
+
+
+cat >>confdefs.h <<_ACEOF
 #define LLVM_DEFAULT_TARGET_TRIPLE "$target"
 _ACEOF