Rename libstd.so to libruststd.so

Fixes Issue #999

Author: lht

Makefile.in

@@ -102,7 +102,7 @@ endif
 
 CFG_RUNTIME :=$(call CFG_LIB_NAME,rustrt)
 CFG_RUSTLLVM :=$(call CFG_LIB_NAME,rustllvm)
-CFG_STDLIB :=$(call CFG_LIB_NAME,std)
+CFG_STDLIB :=$(call CFG_LIB_NAME,ruststd)
 CFG_LIBRUSTC :=$(call CFG_LIB_NAME,rustc)
 
 # version-string calculation