test: Fix spectest failure output

[gumb0]

Before:

Running tests from /home/andrei/dev/wasm-spec/test/core/json/func.json
........................................................................s.FF......ssssssssss..............................ssssssssssss
Line 350: assert_return FAILED Incorrect returned value. Expected: 0 (0x0) Actual: 2a (0x2a)
Line 351: assert_return FAILED Incorrect returned value. Expected: 0 (0x0) Actual: 2a (0x2a)
134 tests ran from func.json.
  PASSED 109, FAILED 2, SKIPPED 23.

After:

Running tests from /home/andrei/dev/wasm-spec/test/core/json/func.json
........................................................................s.FF......ssssssssss..............................ssssssssssss
Line 350: assert_return FAILED Incorrect returned value. Expected: 0 (0x0) Actual: 42 (0x2a)
Line 351: assert_return FAILED Incorrect returned value. Expected: 0 (0x0) Actual: 42 (0x2a)
134 tests ran from func.json.
  PASSED 109, FAILED 2, SKIPPED 23.

[codecov]

Codecov Report

Merging #548 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #548   +/-   ##
=======================================
  Coverage   98.74%   98.74%           
=======================================
  Files          58       58           
  Lines        8765     8765           
=======================================
  Hits         8655     8655           
  Misses        110      110           

[chfast]

Can you add a regression test? In CTest you can check output.

[axic]

And make sure the expected is non-zero so we can see the hex/dec there too.

[axic]

Suggested change

	PASS_REGULAR_EXPRESSION "FAILED Incorrect returned value\\. Expected: 2 \\(0x2\\) Actual: 10 \\(0xa\\)"
	PASS_REGULAR_EXPRESSION "FAILED Incorrect returned value\\. Expected: 12 \\(0xc\\) Actual: 10 \\(0xa\\)"

So that both expected and actual are >9.