Redo "Make instantiateClass more robust when the format is missing"

[guillep]

Redo #629

@privat

[privat]

I'm trying to understand what is the issue with the PR.

build/dist/pharo --logLevel=4 Pharo.image eval '4+4' does not works an seem locked in some loop

[DEBUG] 2023-06-29 15:42:17.000 sqAllocateMemory (src/memoryUnix.c:179):Loading the image in 0x10008831000
[DEBUG] 2023-06-29 15:42:21.000 sqAllocateMemory (src/memoryUnix.c:130):Requested Size 16777216
[DEBUG] 2023-06-29 15:42:21.000 sqAllocateMemory (src/memoryUnix.c:139):Aligned Requested Size 16777216
[DEBUG] 2023-06-29 15:42:21.000 sqAllocateMemory (src/memoryUnix.c:141):Trying to load the image in 0x10009831000
[DEBUG] 2023-06-29 15:42:21.000 sqAllocateMemory (src/memoryUnix.c:179):Loading the image in 0x10009831000
[DEBUG] 2023-06-29 15:42:29.000 sqAllocateMemory (src/memoryUnix.c:130):Requested Size 16777216
[DEBUG] 2023-06-29 15:42:29.000 sqAllocateMemory (src/memoryUnix.c:139):Aligned Requested Size 16777216
[DEBUG] 2023-06-29 15:42:29.000 sqAllocateMemory (src/memoryUnix.c:141):Trying to load the image in 0x1000a831000
[DEBUG] 2023-06-29 15:42:29.000 sqAllocateMemory (src/memoryUnix.c:179):Loading the image in 0x1000a831000

According to git bisect, the issue is in the last commit a9336aa but I have no real idea yet of what is the problem

[guillep]

my take: 0 is a valid format, and nil is translated as NULL, where NULL == 0

[guillep]

Closing in favor of #634