Prepare for VS2017 upgrade - workspace updates

This:
- Generates a VS solution for VS17
- Explicits the boost toolset chosen, leveraging ABI compatibility to
avoid recompiling the library (for now).
- Likewise, reuses the Spidermonkey libraries. The SM60 upgrades does
away with putting the toolset in the library name entirely.

Refs #5862

Differential Revision: https://code.wildfiregames.com/D3130
This was SVN commit r24240.

build/premake/extern_libs5.lua

@@ -184,6 +184,8 @@ extern_lib_defs = {
 	boost = {
 		compile_settings = function()
 			if os.istarget("windows") then
+				-- Force the autolink to use the vc140 libs even on VS2017
+				defines { 'BOOST_LIB_TOOLSET="vc140"' }
 				add_default_include_paths("boost")
 			elseif os.istarget("macosx") then
 				-- Suppress all the Boost warnings on OS X by including it as a system directory
@@ -196,6 +198,9 @@ extern_lib_defs = {
 		end,
 		link_settings = function()
 			if os.istarget("windows") or os.istarget("macosx") then
+				if os.istarget("windows") then
+					defines { 'BOOST_LIB_TOOLSET="vc140"' }
+				end
 				add_default_lib_paths("boost")
 			end
 			add_default_links({
@@ -560,9 +565,9 @@ extern_lib_defs = {
 					pkgconfig.add_links("mozjs-52")
 				end
 			else
-				filter { "Debug", "action:vs2015" }
+				filter { "Debug", "action:vs*" }
 					links { "mozjs52-ps-debug-vc140" }
-				filter { "Release", "action:vs2015" }
+				filter { "Release", "action:vs*" }
 					links { "mozjs52-ps-release-vc140" }
 				filter { "Debug", "action:not vs*" }
 					links { "mozjs52-ps-debug" }

build/premake/premake5.lua

@@ -397,6 +397,8 @@ function project_create(project_name, target_type)
 
 	filter "action:vs2015"
 		toolset "v140_xp"
+	filter "action:vs2017"
+		toolset "v141_xp"
 	filter {}
 
 	filter "action:vs*"
@@ -880,7 +882,7 @@ function setup_all_libs ()
 	end
 
 	-- runtime-library-specific
-	if _ACTION == "vs2015" then
+	if _ACTION == "vs2015" or _ACTION == "vs2017" then
 		table.insert(source_dirs, "lib/sysdep/rtl/msc");
 	else
 		table.insert(source_dirs, "lib/sysdep/rtl/gcc");

build/workspaces/update-workspaces.bat

@@ -3,4 +3,5 @@ rem ** Create Visual Studio Workspaces on Windows **
 
 cd ..\premake
 if not exist ..\workspaces\vc2015\SKIP_PREMAKE_HERE premake5\bin\release\premake5 --outpath="../workspaces/vc2015" --use-shared-glooxwrapper %* vs2015
+if not exist ..\workspaces\vc2017\SKIP_PREMAKE_HERE premake5\bin\release\premake5 --outpath="../workspaces/vs2017" --use-shared-glooxwrapper %* vs2017
 cd ..\workspaces