RFR: Even more gcc warnings

[Mikael Vidstedt]

All,

A drive-by set of warning fixes:

http://cr.openjdk.java.net/~mikael/webrevs/jdk-warnings/jdk-warnings/webrev.00/

Highlights:

* src/share/native/com/sun/java/util/jar/pack/bands.cpp

Set the size of the array explicitly to increase likelihood of enum and 
struct array being in sync. Arguably this should be changed to use the 
(new) [<enumName>] = <value> instead.

Initialize all the fields in the (redundant) terminator struct explicitly.

Remove unused macro.

* src/share/native/sun/java2d/opengl/OGLContext.c

Get the prototype for jio_snprintf from jvm.h to address an implicit 
declaration.

* src/solaris/native/sun/awt/awt_Font.c

Comparisons with string literals is undefined behavior - keep track of 
whether the string should be freed explicitly with a boolean instead.

* src/solaris/native/sun/awt/awt_LoadLibrary.c

The macro is supposed to expand to a void function declaration, but 
forgets to actually add the "void".

Cheers,
Mikael