radv: Win32 fixes

Stub sections that don't have _WIN32 support.

Use standard __VA_ARGS__ macro.

Fix radeon_winsys buffer_create callback signatures.

Fix mutex leak in radv_amdgpu_winsys_destroy().

Replace pthread mutex with mtx_t.

Replace pthread thread with thrd_t.

Exclude amdgpu driver files for Windows.

Use VK_NO_PROTOTYPES to deal with __declspec(dllexport) mismatch.

Add VK_USE_PLATFORM_WIN32_KHR for Windows.

VC++ hates parentheses in typed_memcpy. Remove, and rename to radv_typed_memcpy to avoid collisions with other parts of Mesa.

Create radv_descriptor_set_header for C legality.

Replace VLAs with alloca.

Use unsigned with u_bit_scan.

Use localtime_s instead of localtime_r.

Wrap GCC pragmas with __GNUC__ to fix MSVC warnings.

Create shader cache only if ENABLE_SHADER_CACHE is defined.

Pointer arithmetic on char/uint8_t, not void.

Attempt to implement VK_TIME_DOMAIN_QUERY_PERFORMANCE_COUNTER_EXT.

Use blacklist rather than weak functions for VC++ entrypoints.

Don't return values in void functions.

si_blend_remove_dst on unsigned addresses.

Nullify radv_printflike.

VC++ hates parentheses in radv_assert. Remove. Also switch nonstandard DEBUG with standard NDEBUG, which Aco uses.

Use cross-platform ffs and util_bitcount macros.

Splitting off changes from !6162 (merged).