Void the instructionPointer systematically when creating a base frame

[guillep]

Void the instructionPointer systematically when creating a base fame.

This stops stack manipulations during potential code compactions since we are creating a base frame, and the new page is not entirely initialized.

Callers must make sure that the instruction pointer is saved/stored in suspended frames.

This PR fixes a crash happening in an extreme case when:

1. a base frame is created for a context
2. that context was suspended on machine code
3. the machine code method was garbage collected (thus the method needs to be recompiled to resume)
4. there is no more space in the machine code cache, so a code collection happens

See https://ci.inria.fr/pharo-ci-jenkins2/job/pharo-vm/job/pharo-12/64/pipeline-console/?selected-node=897
The stack trace for this case typically shows the following on a crash:

libPharoVMCore.so(isSendReturnPC+0x2)[0x7fe6be25dbe2]
libPharoVMCore.so(+0xb9a2c)[0x7fe6be2b9a2c]
libPharoVMCore.so(doReport+0xbc)[0x7fe6be2b9d1c]
libPharoVMCore.so(sigsegv+0x14)[0x7fe6be2b9da4]
libc.so.6(+0x3c050)[0x7fe6be05b050]
libPharoVMCore.so(isSendReturnPC+0x2)[0x7fe6be25dbe2]
libPharoVMCore.so(+0x822fc)[0x7fe6be2822fc]
libPharoVMCore.so(ceSendsupertonumArgs+0x1ba)[0x7fe6be2acf3a]