Remove MIPS support

tests/standalone/io/test_extension_test.dart

Index: tests/standalone/io/test_extension_test.dart
diff --git a/tests/standalone/io/test_extension_test.dart b/tests/standalone/io/test_extension_test.dart
index c2c094862352fe77205b86712d768d9851549327..ebef743459e4c0579b60b7c66f2d6c9470402ffb 100644
--- a/tests/standalone/io/test_extension_test.dart
+++ b/tests/standalone/io/test_extension_test.dart
@@ -57,11 +57,9 @@ String getArchFromBuildDir(String buildDirectory) {
   if (buildDirectory.endsWith('SIMARM64')) return '';
   if (buildDirectory.endsWith('SIMDBC')) return '';
   if (buildDirectory.endsWith('SIMDBC64')) return '';
-  if (buildDirectory.endsWith('SIMMIPS')) return '';
   if (buildDirectory.endsWith('ARM')) return '-arm';
   if (buildDirectory.endsWith('ARM64')) return '-arm64';
   if (buildDirectory.endsWith('IA32')) return '-ia32';
-  if (buildDirectory.endsWith('MIPS')) return '-mips';
   if (buildDirectory.endsWith('X64')) return '-x64';
   return 'unknown';
 }