GN: Fix cross ARM64 and cross MIPS builds.

runtime/platform/globals.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_PLATFORM_GLOBALS_H_
 #define RUNTIME_PLATFORM_GLOBALS_H_
 
 // __STDC_FORMAT_MACROS has to be defined before including <inttypes.h> to
 // enable platform independent printf format specifiers.
 #ifndef __STDC_FORMAT_MACROS
@@ skipping 230 matching lines @@
     reinterpret_cast<simd_value_t*>(addr)->data_[1] = value.data_[1];          \
     reinterpret_cast<simd_value_t*>(addr)->data_[2] = value.data_[2];          \
     reinterpret_cast<simd_value_t*>(addr)->data_[3] = value.data_[3];          \
   } while (0)
 
 #elif defined(__MIPSEL__)
 #define HOST_ARCH_MIPS 1
 #define ARCH_IS_32_BIT 1
 #define kFpuRegisterSize 8
 typedef double fpu_register_t;
+#elif defined(__MIPSEB__)
+#error Big-endian MIPS is not supported by Dart. Try passing -EL to your      \
+ compiler.
 #elif defined(__aarch64__)
 #define HOST_ARCH_ARM64 1
 #define ARCH_IS_64_BIT 1
 #define kFpuRegisterSize 16
 typedef simd128_value_t fpu_register_t;
 #else
 #error Architecture was not detected as supported by Dart.
 #endif
 
 // DART_FORCE_INLINE strongly hints to the compiler that a function should
@@ skipping 445 matching lines @@
 // tag in the ICData and check it when recreating the flow graph in
 // optimizing compiler. Enable it for other modes (product, release) if needed
 // for debugging.
 #if defined(DEBUG)
 #define TAG_IC_DATA
 #endif
 
 }  // namespace dart
 
 #endif  // RUNTIME_PLATFORM_GLOBALS_H_