Added the -m option as an alias for -format=darwin to llvm-nm and llvm-size
which is what the darwin tools use for the Mach-O format output.

llvm-svn: 211326
diff --git a/llvm/tools/llvm-size/llvm-size.cpp b/llvm/tools/llvm-size/llvm-size.cpp
index 408bb4a..b71380d 100644
--- a/llvm/tools/llvm-size/llvm-size.cpp
+++ b/llvm/tools/llvm-size/llvm-size.cpp
@@ -46,6 +46,7 @@
        OutputFormatShort(cl::desc("Specify output format"),
          cl::values(clEnumValN(sysv, "A", "System V format"),
                     clEnumValN(berkeley, "B", "Berkeley format"),
+                    clEnumValN(darwin, "m", "Darwin -m format"),
                     clEnumValEnd),
          cl::init(berkeley));