Fix parsing of binary floating point number

* tccpp.c (parse_number): `shift' should be 1 while parsing binary
floating point number.
* tests/tests2/70_floating_point_literals.c: New test cases for
floating point number parsing.

tests/tests2/70_floating_point_literals.expect

@@ -0,0 +1,53 @@
+0.123000
+122999996416.000000
+0.000000
+122999996416.000000
+
+123.123001
+123122997002240.000000
+0.000000
+123122997002240.000000
+
+123.000000
+123000003231744.000000
+0.000000
+123000003231744.000000
+
+123000003231744.000000
+0.000000
+123000003231744.000000
+
+
+428.000000
+0.000026
+428.000000
+
+1756112.000000
+0.104672
+1756592.000000
+
+1753088.000000
+0.104492
+1753088.000000
+
+1753088.000000
+0.104492
+1753088.000000
+
+
+3424.000000
+0.000204
+3424.000000
+
+1756112.000000
+0.104672
+1756112.000000
+
+1753088.000000
+0.104492
+1753088.000000
+
+1753088.000000
+0.104492
+1753088.000000
+