Fix stdlib to be relative to AutoHotkey.exe, not Ahk2Exe

Change /ahk to take priority even if the file doesn't exist (more cautious)

Compiler.ahk

@@ -47,6 +47,20 @@ AhkCompile(ByRef AhkFile, ExeFile="", ByRef CustomIcon="", BinFile="", UseMPRESS
 	DerefIncludeVars.A_PtrSize := BinType.PtrSize
 	DerefIncludeVars.A_IsUnicode := BinType.IsUnicode
 
+	global AhkPath := UseAhkPath
+	if (AhkPath = "")
+	{
+		if !A_IsCompiled
+			AhkPath := A_AhkPath
+		else
+			FileExist(AhkPath := A_ScriptDir "\..\AutoHotkey.exe")
+		 || !BinType.IsUnicode && FileExist(AhkPath := A_ScriptDir "\..\AutoHotkeyA32.exe")
+		 || FileExist(AhkPath := A_ScriptDir "\..\AutoHotkeyU32.exe")
+		 || FileExist(AhkPath := A_AhkPath)
+	}
+	;else even if !FileExist(UseAhkPath), don't fall back to a potentially incompatible EXE.
+	global StdLibDir := Util_GetFullPath(AhkPath "\..\Lib")
+
 	ExeFileG := ExeFile
 	BundleAhkScript(ExeFileTmp, AhkFile, UseMPRESS, CustomIcon, fileCP)
 

ScriptParser.ahk

@@ -171,14 +171,7 @@ PreprocessScript(ByRef ScriptText, AhkScript, ExtraFiles, FileList := "", FirstS
 
 	Loop, % !!IsFirstScript ; Like "if IsFirstScript" but can "break" from block
 	{
-		global AhkPath := UseAhkPath
-		if (AhkPath = "")
-			AhkPath := A_IsCompiled ? A_ScriptDir "\..\AutoHotkey.exe" : A_AhkPath
-		if (!FileExist(AhkPath) && !DerefIncludeVars.A_IsUnicode)
-			AhkPath := A_ScriptDir "\..\AutoHotkeyA32.exe"
-		AhkPath := FileExist(AhkPath) ? AhkPath :A_ScriptDir "\..\AutoHotkeyU32.exe"
-		AhkPath := FileExist(AhkPath) ? AhkPath : A_AhkPath
-
+		global AhkPath
 		IfNotExist, %AhkPath%
 		{	Util_Error("Warning: AutoHotkey.exe could not be located!`n`nAuto-include"
 . "s from Function Libraries, and 'Obey' directives will not be processed.",0)
@@ -235,7 +228,8 @@ IsFakeCSOpening(tline)
 
 FindLibraryFile(name, ScriptDir)
 {
-	libs := [ScriptDir "\Lib", A_MyDocuments "\AutoHotkey\Lib", A_ScriptDir "\..\Lib"]
+	global StdLibDir
+	libs := [ScriptDir "\Lib", A_MyDocuments "\AutoHotkey\Lib", StdLibDir]
 	p := InStr(name, "_")
 	if p
 		name_lib := SubStr(name, 1, p-1)