toolchain: Bump everything to pull in required SPIR-V tools revision

Encompasses pull request #261 from Chris.

Also gets things building again reflecting upstream changesi, mainly
HLSL libs for glslang.

Desktop build/test results w/ update_external_sources.sh/bat
 Windows on Skylake: _run_all_tests.ps1, demos with --validate
 Ubuntu on Skylake: vk_layer_validation_tests, cube --validate

Android build/test results w/ update_external_sources_android.sh/bat:
 Windows: VkLayerValidationTests pass
 OSX: VkLayerValidationTests pass
 Ubuntu: VkLayerValidationTests pass
diff --git a/build-android/shaderc_revision_android b/build-android/shaderc_revision_android
index 04b2324..8187523 100644
--- a/build-android/shaderc_revision_android
+++ b/build-android/shaderc_revision_android
@@ -1 +1 @@
-53cf6692879c6dcd5f4ccdffb8c10bb17b5e9d55
+4213a472474053f456464b7d00d14adf814ecc44