- Update premake build script for VS2017+ build support.

- Update premake (for VS2019 support).
- Update Xenia build script to detect VS2017+ version.
- Update Xenia premake scripts due to updated premake.
- Fix cc override in Xenia build script.

src/xenia/app/premake5.lua

@@ -39,9 +39,6 @@ project("xenia-app")
     "xenia-vfs",
     "xxhash",
   })
-  flags({
-    "WinMain",  -- Use WinMain instead of main.
-  })
   defines({
     "XBYAK_NO_OP_NAMES",
     "XBYAK_ENABLE_OMITTED_OPERAND",

src/xenia/gpu/vulkan/premake5.lua

@@ -59,9 +59,6 @@ project("xenia-gpu-vulkan-trace-viewer")
     "xenia-vfs",
     "xxhash",
   })
-  flags({
-    "WinMain",  -- Use WinMain instead of main.
-  })
   defines({
   })
   includedirs({

src/xenia/hid/premake5.lua

@@ -33,9 +33,6 @@ project("xenia-hid-demo")
     "xenia-ui",
     "xenia-ui-vulkan",
   })
-  flags({
-    "WinMain",  -- Use WinMain instead of main.
-  })
   defines({
     "GLEW_STATIC=1",
     "GLEW_MX=1",

src/xenia/ui/vulkan/premake5.lua

@@ -37,9 +37,6 @@ project("xenia-ui-window-vulkan-demo")
     "xenia-ui-spirv",
     "xenia-ui-vulkan",
   })
-  flags({
-    "WinMain",  -- Use WinMain instead of main.
-  })
   defines({
   })
   includedirs({

src/xenia/vfs/premake5.lua

@@ -26,9 +26,6 @@ project("xenia-vfs-dump")
     "xenia-base",
     "xenia-vfs",
   })
-  flags({
-    -- "WinMain",  -- Use WinMain instead of main.
-  })
   defines({})
   includedirs({
     project_root.."/third_party/gflags/src",