Added -O option (to run python or python_d w/ -O),

PCbuild/rt.bat

@@ -2,28 +2,34 @@
 @rem Plain "rt" runs Release build, arguments passed on to regrtest.
 @rem "rt -d" runs Debug build similarly, after shifting off -d.
 @rem Normally the tests are run twice, the first time after deleting
-@rem all the .py[co] files from Lib/ and Lib/test.  But
+@rem all the .py[co] files from Lib/ and Lib/test/.  But
 @rem "rt -q" (for Quick) runs the tests just once, and without
 @rem bothering to delete .py[co] files.
+@rem "rt -O" runs python or python_d with -O (depending on -d).
 @set _exe=python
 @set _qmode=no
+@set _dashO=
+@goto CheckOpts
+:Again
+@shift
+:CheckOpts
+@if "%1"=="-O" set _dashO=-O
+@if "%1"=="-O" goto Again
 @if "%1"=="-q" set _qmode=yes
-@if "%1"=="-q" shift
+@if "%1"=="-q" goto Again
 @if "%1"=="-d" set _exe=python_d
-@if "%1"=="-d" shift
-@if "%_qmode%"=="yes" goto Qmode
-@if "%1"=="-q" set _qmode=yes
-@if "%1"=="-q" shift
+@if "%1"=="-d" goto Again
 @if "%_qmode%"=="yes" goto Qmode
 @echo Deleting .pyc/.pyo files ...
 @del ..\Lib\*.pyc
 @del ..\Lib\*.pyo
 @del ..\Lib\test\*.pyc
 @del ..\Lib\test\*.pyo
-%_exe% ../lib/test/regrtest.py %1 %2 %3 %4 %5 %6 %7 %8 %9
+%_exe% %_dashO% ../lib/test/regrtest.py %1 %2 %3 %4 %5 %6 %7 %8 %9
 @echo About to run again without deleting .pyc/.pyo first:
 @pause
 :Qmode
-%_exe% ../lib/test/regrtest.py %1 %2 %3 %4 %5 %6 %7 %8 %9
+%_exe% %_dashO% ../lib/test/regrtest.py %1 %2 %3 %4 %5 %6 %7 %8 %9
 @set _exe=
 @set _qmode=
+@set _dashO=