Work around a bug with DSA glNamedBufferData() in SVGA3D driver.

For some reason a buffer *allocated* with this function caused
Mesh::draw() to draw nothing. I gave up on investigating the root cause
-- using non-DSA glBufferData() "just works", so in case of this driver
the "svga3d-broken-dsa-bufferdata" workaround uses the non-DSA code
path.

src/Magnum/Implementation/BufferState.cpp

@@ -178,6 +178,15 @@ BufferState::BufferState(Context& context, std::vector<std::string>& extensions)
     }
     #endif
 
+    #ifndef MAGNUM_TARGET_GLES
+    if(context.isExtensionSupported<Extensions::GL::ARB::direct_state_access>() &&
+      (context.detectedDriver() & Context::DetectedDriver::Svga3D) &&
+      !context.isDriverWorkaroundDisabled("svga3d-broken-dsa-bufferdata"))
+    {
+        dataImplementation = &Buffer::dataImplementationDefault;
+    }
+    #endif
+
     #ifdef MAGNUM_TARGET_GLES
     static_cast<void>(context);
     static_cast<void>(extensions);

src/Magnum/Implementation/driverSpecific.cpp

@@ -88,7 +88,14 @@ namespace {
         /* NaCl advertises some additional extensions but the GLESv2 library
            does not have any entrypoints for them and there is no GetProcAddress
            equivalent, thus marking them as unsupported. */
-        "nacl-missing-extension-entrypoints"
+        "nacl-missing-extension-entrypoints",
+        #endif
+
+        #ifndef MAGNUM_TARGET_GLES
+        /* SVGA3D (VMware host GL driver) glDrawArrays() draws nothing when the
+           vertex buffer memory is initialized using glNamedBufferData() from
+           ARB_DSA. Using the non-DSA glBufferData() works. */
+        "svga3d-broken-dsa-bufferdata",
         #endif
     };
 }