scc runtime for multiple architectures broken between 2.0->2.1

[psifertex]

In BN 2.1 (2020-07-10) and all newer builds, the following fails for all architectures except for x64, and x86:

$ cat test.c
int main() {
    puts("testing!");
    return 0;
}
$ scc2.1 -o /dev/null --arch mips test.c
error: unable to generate code for IL: assign reg1:U32 strlen:U32 reg5:U32
error: code generation failed for function 'fputs'

However, in 2.0 it succeeds:

$ scc2.0 -o /dev/null --arch mips test.c
Output is 2784 bytes

This was almost certainly caused by UB during a change from Make to cmake