PPC/S390: some wasm-spec-tests failing

[jbajwa]

wasm-spec-tests test bucket was added last week and some tests are failing. v8@e177068

>out/Release/d8 --test --random-seed=-976563914 --validate-asm --fast-validate-asm --stress-validate-asm --suppress-asm-messages --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/f32.js
>out/Release/d8 --test --random-seed=-976563914 --validate-asm --fast-validate-asm --stress-validate-asm --suppress-asm-messages --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/f64.js
>out/Release/d8 --test --random-seed=-976563914 --no-turbo --stress-opt --always-opt --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/conversions.js
Stdout:
<WASM>[1]+53: RuntimeError: unreachable
RuntimeError: unreachable
    at <WASM UNNAMED> (<WASM>[1]+53)
    at call (test/wasm-spec-tests/tests/f64.js:37:32)
    at run (test/wasm-spec-tests/tests/f64.js:5028:11)
    at run (test/wasm-spec-tests/tests/f64.js:49:3)
    at test/wasm-spec-tests/tests/f64.js:5028:1

>out/Release/d8 --test --random-seed=-976563914 --noopt --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/skip-stack-guard-page.js
Stderr:
Received signal 11 SEGV_MAPERR 7f4e01ba1a78

==== C stack trace ===============================

 [0x000000d80cdf]
 [0x7f4e06508330]
 [0x00000092a389]
 [0x00000091e61d]
 [0x00000092ea30]
 [0x00000061f6f6]
 [0x00000061f395]
 [0x000000443ea9]
 [0x00000040774e]
 [0x00000040e6e2]
 [0x000000410271]
 [0x000000410ee3]
 [0x7f4e06154f45]
 [0x000000407034]
[end of stack trace]

>out/Release/d8 --test --random-seed=-976563914 --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/float_exprs.js
>out/Release/d8 --test --random-seed=-976563914 --stress-opt --always-opt --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/float_literals.js
>out/Release/d8 --test --random-seed=-976563914 --nohard-abort --nodead-code-elimination --nofold-constants test/wasm-spec-tests/tests/float_memory.js
Stdout:
test/wasm-spec-tests/tests/float_exprs.js:102: Error: Wasm return value -8375792 expected, got -4181488
    throw new Error("Wasm return value " + expected + " expected, got " + actual);
    ^
Error: Wasm return value -8375792 expected, got -4181488
    at assert_return (test/wasm-spec-tests/tests/float_exprs.js:102:11)
    at test/wasm-spec-tests/tests/float_exprs.js:2631:1

[sampsongao]

Fixed test/wasm-spec-tests/tests/float_exprs.js and test/wasm-spec-tests/tests/float_literal.js.
https://codereview.chromium.org/2888533003

[sampsongao]

Disabled test/wasm-spec-tests/tests/f32.js, test/wasm-spec-tests/tests/f32.js, and test/wasm-spec-tests/tests/conversions.js for now.
https://codereview.chromium.org/2921293002

These three tests are failing because ppc and s390 doesn't convert sNaN to qNaN. . For f32.js and f64.js, the problem is in float min and float max and for conversions.js, it is in double to float conversion.

The next step is either only skip the specific test cases or change the output checking logic to accept both sNaN and qNaN.