Build: Verify that we're compiling with C++14.

Better to have a descriptive compiler error message than weird missing symbols.

Bug: b/147359661
Change-Id: I66c0e5beb1e94f79210528867c990ab3e0f8b0ae
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/39949
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
diff --git a/src/Android.bp b/src/Android.bp
index 081a58a..79bb946 100644
--- a/src/Android.bp
+++ b/src/Android.bp
@@ -571,6 +571,7 @@
     ],
 
     srcs: [
+        "System/Build.cpp",
         "System/CPUID.cpp",
         "System/Configurator.cpp",
         "System/Half.cpp",