Undefined behaviour in unit tests

[andrewstanfordjason]

We should fix this:

src/c/maxpool2d.c:137:57: runtime error: unsigned integer overflow: 32 - 64 cannot be represented in type 'unsigned int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/c/maxpool2d.c:137:57 in
src/test_maxpool2d.c:359:test_maxpool2d_case0:PASS
src/test_maxpool2d.c:360:test_maxpool2d_case1:PASS
src/c/avgpool2d.c:198:58: runtime error: unsigned integer overflow: 16 - 32 cannot be represented in type 'unsigned int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/c/avgpool2d.c:198:58 in
src/test_avgpool2d.c:552:test_avgpool2d_case0:PASS
src/test_avgpool2d.c:274:34: runtime error: implicit conversion from type 'unsigned int' of value 204 (32-bit, unsigned) to type 'int8_t' (aka 'signed char') changed the value to -52 (8-bit, signed)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_avgpool2d.c:274:34 in
src/test_avgpool2d.c:553:test_avgpool2d_case1:PASS
src/test_avgpool2d.c:554:test_avgpool2d_case2:PASS
src/test_avgpool2d.c:555:test_avgpool2d_case3:PASS
src/test_avgpool2d.c:556:test_avgpool2d_case4:PASS
src/test_avgpool2d.c:557:test_avgpool2d_case5:PASS
src/test_avgpool2d_global.c:277:test_avgpool2d_global_case0:PASS
src/test_avgpool2d_global.c:189:36: runtime error: unsigned integer overflow: 4294967286 * 2 cannot be represented in type 'unsigned int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_avgpool2d_global.c:189:36 in
src/test_avgpool2d_global.c:189:54: runtime error: unsigned integer overflow: 4294967276 * 2 cannot be represented in type 'unsigned int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_avgpool2d_global.c:189:54 in
src/test_avgpool2d_global.c:201:45: runtime error: unsigned integer overflow: 24 + 4294967286 cannot be represented in type 'unsigned int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_avgpool2d_global.c:201:45 in
src/test_avgpool2d_global.c:278:test_avgpool2d_global_case1:PASS
src/test_avgpool2d_global.c:264:24: runtime error: implicit conversion from type 'int' of value 204 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -52 (8-bit, signed)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_avgpool2d_global.c:264:24 in
src/test_avgpool2d_global.c:279:test_avgpool2d_global_case2:PASS
src/test_requantize_16_to_8.c:298:test_requantize_16_to_8_case0:PASS
src/test_requantize_16_to_8.c:127:24: runtime error: implicit conversion from type 'int' of value 204 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -52 (8-bit, signed)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_requantize_16_to_8.c:127:24 in
src/test_requantize_16_to_8.c:299:test_requantize_16_to_8_case1:PASS
src/test_requantize_16_to_8.c:183:24: runtime error: implicit conversion from type 'int' of value 204 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -52 (8-bit, signed)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_requantize_16_to_8.c:183:24 in
src/test_requantize_16_to_8.c:300:test_requantize_16_to_8_case2:PASS
src/test_requantize_16_to_8.c:248:24: runtime error: implicit conversion from type 'int' of value 204 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -52 (8-bit, signed)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_requantize_16_to_8.c:248:24 in
src/test_requantize_16_to_8.c:272:30: runtime error: implicit conversion from type 'int' of value 204 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -52 (8-bit, signed)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/test_requantize_16_to_8.c:272:30 in