RFR: JDK-8026773: Failing compilation in Corba does not fail the build

[Erik Joelsson]

Here is a patch which has the primary purpose of eliminating a certain 
makefile construct that was introduced in build-infra and used in 
langtools and corba. The trick was clever, but unfortunately had the 
drawback of the build not always failing on errors, or giving very weird 
error messages. Here is the bug and the patch:

Bug: https://bugs.openjdk.java.net/browse/JDK-8026773
Webrev: http://cr.openjdk.java.net/~erikj/8026773/webrev.01/

A bit of background is probably needed. The problem that needs to be 
solved is that when we use SetupJavaCompilation to compile java, all the 
source files must exist on disk when make starts parsing the makefile. 
Any non existing java files will not be discovered by the macro and will 
then not be compiled. So if there are java sources being generated by a 
rule in the same makefile, these will not be visible to 
SetupJavaCompilation.

In the jdk repo this is solved by separating source generation and java 
compilation into different makefiles and make explicit calls to them in 
order. While this would work here to, I don't think we should enforce 
separation for implementation purposes when it doesn't really make sense 
from a logical grouping point of view. In the case of Corba and 
Langtools, I do not think this separation makes sense for code 
readability, so I chose to solve it with a recursive call back to the 
same makefile for specific parts of the file.

While working in this area, I couldn't help but spend some time cleaning 
up. The Langtools and Corba repos were the first to be converted to 
build-infra, and didn't follow styles and conventions that were 
introduced later. I also cleaned up comments.

/Erik