[x87] Enable test cases which failed at know issue that x87 change sNaN to qNaN by default.

test/mjsunit/mjsunit.status

Index: test/mjsunit/mjsunit.status
diff --git a/test/mjsunit/mjsunit.status b/test/mjsunit/mjsunit.status
index 017fa4dfa943532ba0ae951da5b7afd8bf16d888..7ce8286cf4805609ffd7dece508a8932e63adb8b 100644
--- a/test/mjsunit/mjsunit.status
+++ b/test/mjsunit/mjsunit.status
@@ -648,13 +648,7 @@
 }],  # 'arch == mips'
 
 ##############################################################################
-['arch == x87', {
-  # Turbofan will hit the known issue that x87 changes sNaN to qNaN by default.
-  'regress/regress-undefined-nan': [SKIP],
-  'regress/regress-crbug-242924': [SKIP],
-}],  # 'arch == x87'
 
-##############################################################################
 ['arch == mips64el or arch == mips64', {
 
   # Slow tests which times out in debug mode.