Renderer: Fix deadlock when calling Renderer::draw() with a count of 0.
Renderer: Fix deadlock when calling Renderer::draw() with a count of 0.

Tests: dEQP-VK.draw.basic_draw.draw_indirect.*
Tests: dEQP-VK.draw.basic_draw.draw_indexed_indirect.*
Bug: b/133127573
Change-Id: Ie64ae58d352d0fab23a0ce8811ce95c024e59367
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31687
Tested-by: Ben Clayton <1f693eb7158dc33015048c09d6712f74dabddf79@google.com>
Reviewed-by: Alexis Hétu <1c7141772178a7e80858c3db5052b328076f08f4@google.com>
Reviewed-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Reviewed-by: Chris Forbes <c3279c50043e18e9442c1ae071cafa0e7a4ca967@google.com>
Kokoro-Presubmit: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

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