Tools require EH for their top-level try blocks.

llvm-svn: 29035
diff --git a/llvm/tools/llvm-as/Makefile b/llvm/tools/llvm-as/Makefile
index 73dcb06..bd7c3d3 100644
--- a/llvm/tools/llvm-as/Makefile
+++ b/llvm/tools/llvm-as/Makefile
@@ -10,5 +10,6 @@
 TOOLNAME = llvm-as
 USEDLIBS = LLVMAsmParser.a LLVMBCWriter.a LLVMCore.a \
            LLVMSupport.a LLVMbzip2.a LLVMSystem.a
+REQUIRES_EH := 1
 
 include $(LEVEL)/Makefile.common