Some of the test cases of #1780 cause uninitialized memory to be written
to the output file due to incomplete reads. This causes subsequent tests
to fail their checksums. Therefore only record the fact that they've
completed successfully.
No one guarantees us that the duration map size & number values really
sum to no more than the number of sample table entries in the
file. Therefore check the current sample table index against the sample
table's size before accessing the table.
Fixes the following test cases of #1780:
explorer🆔000011,sig:11,src:000001,op:flip1,pos:42
explorer🆔000012,sig:11,src:000001,op:flip1,pos:13438
explorer🆔000014,sig:11,src:000001,op:flip1,pos:13457
explorer🆔000030,sig:11,src:000001,op:flip1,pos:13798
explorer🆔000031,sig:11,src:000001,op:flip1,pos:13798
explorer🆔000032,sig:11,src:000001,op:flip1,pos:13798
explorer🆔000063,sig:06,src:000001,op:arith8,pos:13794,val:-13
explorer🆔000083,sig:06,src:000005,op:flip1,pos:3
explorer🆔000097,sig:06,src:000005,op:flip1,pos:13730
explorer🆔000129,sig:06,src:000005,op:flip1,pos:13801
explorer🆔000144,sig:11,src:000005,op:flip2,pos:13866
explorer🆔000231,sig:11,src:000005,op:havoc,rep:16
explorer🆔000261,sig:11,src:000013,op:arith8,pos:13647,val:+7
explorer🆔000318,sig:11,src:000287,op:flip2,pos:13797
explorer🆔000323,sig:06,src:000314,op:flip1,pos:13731
explorer🆔000324,sig:06,src:000314,op:havoc,rep:64
explorer🆔000347,sig:06,src:000426,op:flip1,pos:13797
explorer🆔000353,sig:11,src:000426,op:flip1,pos:13823
explorer🆔000354,sig:11,src:000426,op:flip1,pos:13825
explorer🆔000357,sig:11,src:000426,op:flip2,pos:13825
explorer🆔000358,sig:06,src:000426,op:flip2,pos:13826
