Fix a memory leak

found by clang-analyzer
Avoid undefined behavior caused by malloc(0)

Found by clang-analyzer
Fix memory leaks

Found by clang-analyzer
Merge branch 'atronix' into coverity_scan
Fix unintended assignement

Found by coverity
Fix a comparison between unsigned int and zero

Found by coverity
Fix parameter to Remove_Series

The "n" to Remove_Series should be the number of elements to be removed
from the series, not the size of the element in bytes, as the width of
the series is sizeof(REBSER *) (See Init_Memory in m-gc.c)

It should only remove the series in question.
Promote integer type in overflow detection

without promotion, *sum is i32, and will always be within the range of
[MIN_I32, MAX_I32]
Add a coverity annotation
Merge branch 'atronix' into coverity_scan