TSAN will catch this, but when its disabled, everything simply freezes and you have to go hunting across all the threads in the debugger.
Just explode immediately with a sensible message.

Bug: b/145351270
Change-Id: Iecef77a47bd54daabb489c5ca70e44b68c0c1e1f
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/48692
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>