[Fix] (Build): restore the MSVC Windows build of the opengl32 drop-in

MobileGL/MG_Impl/EGLImpl/Exporting/GlvndVendor.cpp

@@ -348,8 +348,16 @@ namespace {
     void* EGLAPIENTRY VendorGetDispatchAddress(const char* procName) { return LookupEntryPoint(procName); }
 }  // namespace
 
-extern "C" MOBILEGL_EGL_API EGLBoolean __egl_Main(uint32_t version, const __EGLapiExports* exports,
-                                                  __EGLvendorInfo* vendor, __EGLapiImports* imports) {
+// libeglabi.h has already declared this prototype without an export attribute, and MSVC refuses a
+// redeclaration that adds dllexport. Windows has no glvnd to look the symbol up, so it is a plain
+// external definition there.
+#ifdef _WIN32
+#define MOBILEGL_GLVND_EGL_MAIN extern "C"
+#else
+#define MOBILEGL_GLVND_EGL_MAIN MOBILEGL_EGL_API
+#endif
+MOBILEGL_GLVND_EGL_MAIN EGLBoolean __egl_Main(uint32_t version, const __EGLapiExports* exports,
+                                              __EGLvendorInfo* vendor, __EGLapiImports* imports) {
     (void)vendor;
     if (EGL_VENDOR_ABI_GET_MAJOR_VERSION(version) != EGL_VENDOR_ABI_MAJOR_VERSION) {
         // A vendor that does not know the ABI it is being handed must say so, not guess: the

MobileGL/MG_Impl/Pipe/TextureEmit.h

@@ -1634,7 +1634,7 @@ namespace MobileGL::MG_Pipe {
                             rectBoxes, rectCount, slab, pitch, m_regions.data(), m_regions.size());
                         m_regions.resize(pieceRegions);
                         fillRecord(slab.Box,
-                                   reinterpret_cast<Uint64>(reinterpret_cast<std::uintptr_t>(shadow)) +
+                                   static_cast<Uint64>(reinterpret_cast<std::uintptr_t>(shadow)) +
                                        slab.RunOffset);
                         const Bool pieceAccepted = emitRecord(
                             static_cast<const Uint8*>(shadow) + slab.RunOffset, slab.RunBytes);

MobileGL/MG_State/GLState/BufferState/PersistentMapTracker.cpp

@@ -23,6 +23,7 @@
 #include <Config.h>
 
 #include <atomic>
+#include <bit>
 #include <cstdlib>
 #include <cstring>
 
@@ -1012,7 +1013,7 @@ namespace MobileGL::MG_Record {
                 for (SizeT wordIndex = 0; wordIndex < (tracked->pageCount + 63) / 64; ++wordIndex) {
                     Uint64 word = tracked->pageBits[wordIndex].load(std::memory_order_relaxed);
                     while (word != 0) {
-                        const SizeT bit = static_cast<SizeT>(__builtin_ctzll(word));
+                        const SizeT bit = static_cast<SizeT>(std::countr_zero(word));
                         word &= word - 1;
                         const SizeT pageIndex = (wordIndex << 6) + bit;
                         // Clear the bit FIRST, per the order the correctness argument
@@ -1026,7 +1027,7 @@ namespace MobileGL::MG_Record {
                                                                std::memory_order_relaxed);
                         SizeT runEnd = pageIndex + 1;
                         while (word != 0) {
-                            const SizeT nextBit = static_cast<SizeT>(__builtin_ctzll(word));
+                            const SizeT nextBit = static_cast<SizeT>(std::countr_zero(word));
                             if ((wordIndex << 6) + nextBit != runEnd) break;
                             word &= word - 1;
                             tracked->pageBits[wordIndex].fetch_and(~(1ull << nextBit),