Several small issues builfing openjdk on opensolaris

1. Besides the mini guide on http://openjdk.java.net/install/, in order to build the deploy ws:
   
      Install Mozilla header files and set ALT_MOZILLA_HEADERS_PATH.

2. ALT_DEVTOOLS_PATH must be set. This is not mentioned in the mini guide.

3. While compiling hotspot:
      WARNING: You are using CC version and should be using version 5.9.
               Set ENFORCE_COMPILER_REV= to avoid this warning.
      ....
      gmake[7]: CC: Command not found
   Seems ALT_COMPILER_PATH is not fed into hotspot build. One workaround is adding /opt/SunStudioExpress/bin/ to $PATH.

4. In hotspot:
   "/myjdk/hotspot/src/share/vm/runtime/vframe.cpp", line 104: Error: Ambiguous "?:" expression, second operand of type "oop" and third operand of type "int" can be converted to one another.
   "/myjdk/hotspot/src/share/vm/runtime/vframe.cpp", line 105: Error: Ambiguous "?:" expression, second operand of type "oop" and third operand of type "int" can be converted to one another.
   You can changes "NULL" to "(oop)NULL"

5. The -ldga problem mentioned in 6792287