[Feat, Test] (MG_Impl, MG_State, MG_Util): opt-in MOBILEGL_ASYNC_OPTIMISTIC_SHADER_STATUS - shader compile status/log answer without joining, latched per compile

MobileGL/MG_Util/Async/ShaderCompilePool.cpp

@@ -126,6 +126,15 @@ namespace MobileGL::MG_Util::Async {
         return AsyncShaderCompileEnabled() && !IsAsyncShaderCompileSuspended();
     }
 
+    Bool OptimisticShaderStatusActive() {
+        switch (MG_Config::Features.AsyncOptimisticShaderStatus) {
+        case MG_Config::QuirkOverride::ForceOn: return AsyncShaderCompileActive();
+        case MG_Config::QuirkOverride::ForceOff: return false;
+        case MG_Config::QuirkOverride::Auto: break;
+        }
+        return kOptimisticShaderStatusDefault && AsyncShaderCompileActive();
+    }
+
     Uint DetectShaderCompileThreadCount() {
         if (const Uint32 configured = MG_Config::Features.AsyncShaderCompileThreads; configured > 0) {
             // An explicit request is honoured as given - it is the escape hatch for measuring

MobileGL/MG_Util/Async/ShaderCompilePool.h

@@ -59,6 +59,21 @@ namespace MobileGL::MG_Util::Async {
     // GL_COMPLETION_STATUS_KHR read immediately GL_TRUE.
     Bool AsyncShaderCompileActive();
 
+    // MOBILEGL_ASYNC_OPTIMISTIC_SHADER_STATUS (see Config.h): opt-in, off by default, and a
+    // spec violation by design - GL_COMPILE_STATUS and the shader info log answer
+    // optimistically while the compile job is in flight instead of joining it. Do not flip
+    // this default without an enumerated CTS delta: the compile-error-reporting cases WILL
+    // regress under it, deliberately.
+    inline constexpr Bool kOptimisticShaderStatusDefault = false;
+
+    // The one question the three optimistic getter sites ask. ANDed with
+    // AsyncShaderCompileActive() so that async-off (env kill switch) and
+    // glMaxShaderCompilerThreadsKHR(0) both switch the quirk off structurally: in those
+    // modes every compile settles before its enqueue returns, so a non-terminal node - the
+    // only state the quirk changes - cannot exist, and keeping the AND means there is no
+    // new mode interaction to reason about.
+    Bool OptimisticShaderStatusActive();
+
     // min(4, big cores), where a big core is one whose cpufreq ceiling is within 15% of the
     // machine maximum; the whole CPU count where that sysfs tree is absent. Clamped to [1, 4]
     // because peak RSS scales as workers x largest glslang arena, and four