Reset TLS when the EGL context is destroyed.
Reset TLS when the EGL context is destroyed.

Bug 20045861

Change-Id: I16e76a464f58ffb47ed92374cf9d2aef21cc7603
Reviewed-on: https://swiftshader-review.googlesource.com/2783
Reviewed-by: Alexis Hétu <1c7141772178a7e80858c3db5052b328076f08f4@google.com>
Reviewed-by: Nicolas Capens <0612353e1fcebbfd4b302d9337447ca0cdfa9122@google.com>
Tested-by: Nicolas Capens <0612353e1fcebbfd4b302d9337447ca0cdfa9122@google.com>

bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,google/swiftshader