Preliminary request for review: 7025066 Build system changes to support SE Embedded integration

[David Holmes]

http://cr.openjdk.java.net/~dholmes/7025066/webrev/

The SE-Embedded product is a combination of open and closed sources. To 
allow SE-Embedded to be built from standard OpenJDK sources we need to 
apply a number of changes to the SE 7 build system:

- support for building the hotspot client compiler only (hotspot already 
supports this, this is the JDK side of things)
- support for doing cross-compilation (Linux only)
- minimal support for ARM/PPC architectures in the open code that 
currently only knows about x86 and sparc
- SE-Embedded specific build settings and targets (specifically the 
headful and headless reduced JRE images)

---

These changes are obviously primarily for Oracle's benefit, but some 
aspects may be use of externally as well. The hope is that these changes 
won't have an adverse affect on any downstream OpenJDK builders, but 
until I get feedback on that I won't know.

Thanks,
David Holmes
SE Embedded Team