OGL: Use glBufferData on Mali.

tl;dr: This PR speedups dolphin on mobiles with the Mali GPU and ES 3.2
drivers by a factor of 10 by using the method with the biggest overhead.
Please keep care not to buy this shit!

The ARM driver team seems to care very well about their customers. But
bad luck, users and open source developers are *not* their customers. So
even device-independent feature requests are just ignored for *years*:

https://community.arm.com/graphics/f/discussions/4645/gl_ext_buffer_storage-support

The bad point, they neither implement any of the other common ways to
stream dynamic content in unextented GL:
- They just ignore the GL_MAP_UNSYNCHRONIZED_BIT flag
- They don't support on-device buffer updates and just stall with
glBufferSubData

It seems like no benchmark is using any dynamic content - and like no
customer cares about anything but benchmarks, or users...

We have a flag to disable the glBufferSubData way, this PR adds the flag
to also disable the unsychronized mapping way. The second one is
available since their ES 3.2 update, but slow as hell.

So how to continue? The last remaining technical way to stream dynamic
content at all is to alloc a new buffer per draw call with glBufferData.
This is very gross, but still a factor 10 speedup compared to stalling
the GPU. Small tests shows that you can expect another 3-5 times speedup
with EXT_buffer_data, so Mali would be on pair with Adreno here. So if
you have bought such a device unfortunately, please try to make noise on
your vendor forums/support and ask for this extension. If you are going
to buy a new mobile, I'd recormend to avoid *any* mobile with a Mali GPU
in it.

Source/Core/VideoBackends/OGL/StreamBuffer.cpp

@@ -376,7 +376,12 @@ std::unique_ptr<StreamBuffer> StreamBuffer::Create(u32 type, u32 size)
 
     // don't fall back to MapAnd* for Nvidia drivers
     if (DriverDetails::HasBug(DriverDetails::BUG_BROKEN_UNSYNC_MAPPING))
-      return std::make_unique<BufferSubData>(type, size);
+    {
+      if (DriverDetails::HasBug(DriverDetails::BUG_BROKEN_BUFFER_STREAM))
+        return std::make_unique<BufferData>(type, size);
+      else
+        return std::make_unique<BufferSubData>(type, size);
+    }
 
     // mapping fallback
     if (g_ogl_config.bSupportsGLSync)

Source/Core/VideoCommon/DriverDetails.cpp

@@ -82,6 +82,8 @@ static BugInfo m_known_bugs[] = {
      BUG_BROKEN_UNSYNC_MAPPING, -1.0, -1.0, true},
     {API_OPENGL, OS_LINUX, VENDOR_NVIDIA, DRIVER_NVIDIA, Family::UNKNOWN, BUG_BROKEN_UNSYNC_MAPPING,
      -1.0, -1.0, true},
+    {API_OPENGL, OS_ALL, VENDOR_ARM, DRIVER_ARM, Family::UNKNOWN, BUG_BROKEN_UNSYNC_MAPPING, -1.0,
+     -1.0, true},
     {API_OPENGL, OS_WINDOWS, VENDOR_INTEL, DRIVER_INTEL, Family::UNKNOWN,
      BUG_INTEL_BROKEN_BUFFER_STORAGE, 101810.3907, 101810.3960, true},
     {API_OPENGL, OS_ALL, VENDOR_ATI, DRIVER_ATI, Family::UNKNOWN, BUG_SLOW_GETBUFFERSUBDATA, -1.0,

Source/Core/VideoCommon/DriverDetails.h

@@ -125,13 +125,17 @@ enum Bug
   // Intel HD 4000 series isn't affected by the bug
   BUG_PRIMITIVE_RESTART,
   // Bug: unsync mapping doesn't work fine
-  // Affected devices: Nvidia driver
+  // Affected devices: Nvidia driver, ARM Mali
   // Started Version: -1
   // Ended Version: -1
   // The Nvidia driver (both Windows + Linux) doesn't like unsync mapping performance wise.
   // Because of their threaded behavior, they seem not to handle unsync mapping complete unsync,
   // in fact, they serialize the driver which adds a much bigger overhead.
   // Workaround: Use BufferSubData
+  // The Mali behavior is even worse: They just ignore the unsychronized flag and stall the GPU.
+  // Workaround: As they were even too lazy to implement asynchronous buffer updates,
+  //             BufferSubData stalls as well, so we have to use the slowest possible path:
+  //             Alloc one buffer per draw call with BufferData.
   // TODO: some Windows AMD driver/GPU combination seems also affected
   //       but as they all support pinned memory, it doesn't matter
   BUG_BROKEN_UNSYNC_MAPPING,