Testing: Add new tests, and new ways of testing, for floating-point.

- Adds a pragma to see binary output of double values (not portable)
- Print decimals that show more values, but in a portable way
  (lots of portability issues)
- Expand the tests to test more double values

Note: it is quite difficult to have 100% portable tests for floating point.
The current situation works by not printing full precision, and working around
several portability issues.

Test/cppPassMacroName.frag

@@ -2,6 +2,10 @@
 #define I2(f, n) f(n) + f(n+1)
 #define I3(f, n) I2(f, n) + f(n+2)
 
+#define FL_f1(i) ((i)*(i))
+#define FL_I2(f, n) f(n) + f(n+0.2)
+#define FL_I3(f, n) FL_I2(f, n) + f(n+0.5)
+
 void main()
 {
     int f1 = 4;
@@ -9,4 +13,18 @@ void main()
     int f3 = f1(3);
     int f4 = I2(f1, 0);
     int f5 = I3(f1, 0);
+
+    highp float fl_f5 = FL_I3(FL_f1, 0.1);
 }
+
+// f5 = I3(f1, 0)
+//    = I2(f1, 0) + f1(0 + 2)
+//    = f1(0) + f1(0+1) + f1(0+2)
+//    = 0*0 + 1*1 + 2*2
+//    = 5
+
+// fl_f5 = FL_I3(FL_f1, 0.1)
+//       = FL_I2(FL_f1, 0.1) + FL_f1(0.1 + 0.5)
+//       = FL_f1(0.1) + FL_f1(0.1 + 0.2) + FL_f1(0.1 + 0.5)
+//       = 0.1*0.1 + 0.3*0.3 + 0.6*0.6
+//       = 0.46