Fix the broken semicolon separated list arguments for configure

When evaluating the arguments from the config.tl.opt file we need
to consider that arguments may contain the escaped semicolons for
the list arguments. The escaped semicolons '\;' needs to be converted
to a CMake brace escaped sequence to make sure that semicolon persist
when running the command.

Fixes: QTBUG-124265
Change-Id: I051f856b43f75b0bac17ae13bd8c7de540f8c794
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

cmake/QtIRCommandLineHelpers.cmake

@@ -244,6 +244,7 @@ endfunction()
 # Reads the command line arguments from the optfile_path.
 function(qt_ir_get_raw_args_from_optfile optfile_path out_var)
     file(STRINGS "${optfile_path}" args)
+    qt_ir_escape_semicolons(args "${args}")
     set(${out_var} "${args}" PARENT_SCOPE)
 endfunction()