Add option to specify compiler executable.

Change-Id: I973da5e74be5a62461caacbc708288fb95e1b99b
diff --git a/runtime/parsed_options.cc b/runtime/parsed_options.cc
index 3756435..db2a61b 100644
--- a/runtime/parsed_options.cc
+++ b/runtime/parsed_options.cc
@@ -15,6 +15,7 @@
  */
 
 #include "parsed_options.h"
+#include "utils.h"
 #ifdef HAVE_ANDROID_OS
 #include "cutils/properties.h"
 #endif
@@ -604,6 +605,10 @@
           return false;
         }
       }
+    } else if (StartsWith(option, "-Xcompiler:")) {
+      if (!ParseStringAfterChar(option, ':', &compiler_executable_)) {
+        return false;
+      }
     } else if (option == "-Xcompiler-option") {
       i++;
       if (i == options.size()) {
@@ -791,6 +796,7 @@
   UsageMessage(stream, "  -Xprofile-duration:integervalue\n");
   UsageMessage(stream, "  -Xprofile-interval:integervalue\n");
   UsageMessage(stream, "  -Xprofile-backoff:doublevalue\n");
+  UsageMessage(stream, "  -Xcompiler:filename\n");
   UsageMessage(stream, "  -Xcompiler-option dex2oat-option\n");
   UsageMessage(stream, "  -Ximage-compiler-option dex2oat-option\n");
   UsageMessage(stream, "\n");