[ieboilstart] Possible conflict with data frames

[luizaandrade]

The following code

ieboilstart, v(17.0)
`r(version)'

sysuse auto, clear

preserve

ieboilstart, v(17.0)
`r(version)'

Returns the following error message:

multiple frames in memory
r(459);

We may need to figure out how to clear all data frames