Don't coerce NAN values to strings due to warnings

Author: alcaeus

tests/bson/bson-decimal128-002.phpt

@@ -4,8 +4,6 @@ MongoDB\BSON\Decimal128 NaN values
 <?php
 
 $tests = [
-    acos(8),
-    NAN,
     'nan',
     'Nan',
     'NaN',
@@ -24,6 +22,4 @@ NaN
 NaN
 NaN
 NaN
-NaN
-NaN
 ===DONE===

tests/bson/bson-decimal128-004.phpt

@@ -4,9 +4,9 @@ MongoDB\BSON\Decimal128 debug handler
 <?php
 
 $tests = [
-    1234.5678,
-    NAN,
-    INF,
+    '1234.5678',
+    'NAN',
+    'INF',
 ];
 
 foreach ($tests as $test) {

tests/bson/bson-decimal128-serialization-002.phpt

@@ -6,9 +6,9 @@ MongoDB\BSON\Decimal128 serialization (__serialize and __unserialize)
 $tests = [
     '1234.5678',
     '-1234.5678',
-    1234.56e-78,
-    INF,
-    NAN,
+    '1234.56e-78',
+    'INF',
+    'NAN',
 ];
 
 foreach ($tests as $value) {