Various fixes in setting globals in a script group

Bug: 25602504

1) Passing floating point values into a script group was broken,
since they were casted to long values. Fixed that in the frameworks
implementation by taking the raw bits instead.

2) Passing 64-bit values into a script group was broken on 32-bit
platforms, since they were casted to pointer-sized integers
(uintptr_t) in the JNI code. Fixed that by casting to int64_t
instead.

3) Setting global variables of Allocation type in a script group was
broken. The special size value -1 was used to indicate the value is an
Allocation. However, size was casted to size_t in the JNI code.
Fixed that by using signed integers.

Change-Id: Ifff099a76be7707df7b67c388395f5a00f9cae66
diff --git a/rs/java/android/renderscript/ScriptGroup.java b/rs/java/android/renderscript/ScriptGroup.java
index 54180f4..9bbacbc 100644
--- a/rs/java/android/renderscript/ScriptGroup.java
+++ b/rs/java/android/renderscript/ScriptGroup.java
@@ -278,6 +278,8 @@
             public ValueAndSize(RenderScript rs, Object obj) {
                 if (obj instanceof Allocation) {
                     value = ((Allocation)obj).getID(rs);
+                    // Special value for size to tell the runtime and driver that
+                    // the value is an Allocation
                     size = -1;
                 } else if (obj instanceof Boolean) {
                     value = ((Boolean)obj).booleanValue() ? 1 : 0;
@@ -289,10 +291,10 @@
                     value = ((Long)obj).longValue();
                     size = 8;
                 } else if (obj instanceof Float) {
-                    value = ((Float)obj).longValue();
+                    value = Float.floatToRawIntBits(((Float)obj).floatValue());
                     size = 4;
                 } else if (obj instanceof Double) {
-                    value = ((Double)obj).longValue();
+                    value = Double.doubleToRawLongBits(((Double)obj).doubleValue());
                     size = 8;
                 }
             }