Add support for building the Dart VM for Android OS.

runtime/bin/platform_android.cc

Index: runtime/bin/platform_android.cc
diff --git a/runtime/bin/platform_macos.cc b/runtime/bin/platform_android.cc
similarity index 90%
copy from runtime/bin/platform_macos.cc
copy to runtime/bin/platform_android.cc
index 81455ba3d3988ae7348433d517836d4b83fb96ed..f5f961b35b0f0fd954dfdb1c921736147d71af81 100644
--- a/runtime/bin/platform_macos.cc
+++ b/runtime/bin/platform_android.cc
@@ -4,7 +4,6 @@
 
 #include "bin/platform.h"
 
-#include <crt_externs.h>
 #include <signal.h>
 #include <string.h>
 #include <unistd.h>
@@ -31,7 +30,7 @@ int Platform::NumberOfProcessors() {
 
 
 const char* Platform::OperatingSystem() {
-  return "macos";
+  return "linux";

[cshapiro, 2012/08/07 20:56:54]

Why isn't this "android"?

[jackpal, 2012/08/07 21:43:26]

Done.

 }
 
 
@@ -43,9 +42,6 @@ bool Platform::LocalHostname(char *buffer, intptr_t buffer_length) {
 char** Platform::Environment(intptr_t* count) {
   // Using environ directly is only safe as long as we do not
   // provide access to modifying environment variables.
-  // On MacOS you have to do a bit of magic to get to the
-  // environment strings.
-  char** environ = *(_NSGetEnviron());
   intptr_t i = 0;
   char** tmp = environ;
   while (*(tmp++) != NULL) i++;
@@ -62,6 +58,7 @@ char* Platform::StrError(int error_code) {
   static const int kBufferSize = 1024;
   char* error = static_cast<char*>(malloc(kBufferSize));
   error[0] = '\0';
+  // Android has a XSI-compliant version of strerror_r.

[cshapiro, 2012/08/07 20:56:54]

This comment does not provide much useful information.

[jackpal, 2012/08/07 21:43:26]

Removed...

   strerror_r(error_code, error, kBufferSize);
   return error;
 }