Updated runtest to always rebuild libtangobos-partial.a in case of updates.

Changed std.stdarg to import ldc.vararg so it has the correct implementation.

tests/runtest

@@ -7,13 +7,11 @@ if [ -z "$1" ] ; then
 fi
 TARGETFILE=$1
 
-# check for libtangobos-partial
-if ! [ -f testincludes/libtangobos-partial.a ] ; then
-    echo "Could not find libtangobos-partial.a, attempting to build."
-    cd testincludes
-    make
-    cd ..
-fi
+# build libtangobos-partial
+echo "Building libtangobos-partial.a"
+cd testincludes
+make
+cd ..
 
 # check for dstress
 if ! [ -d dstress ] ; then