RFR: JDK-8148120 Incremental update from build-infra project

[Magnus Ihse Bursie]

This patch contains a series of small fixes of general applicability 
that have been created in the build-infra project. These are:

* Add missing llvm library dependency
* Improve compare script for static libraries
* Simplify LogFailures interface, and add support for storing command lines
* Hide "Creating library *.lib and object *.exp" text when linking on 
Windows
* Fix problems with smartjavac when using the build-compare functionality
* When repeating output, truncate it if too long

Bug: https://bugs.openjdk.java.net/browse/JDK-8148120
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8148120-incremental-updates-from-build-infra/webrev.01

/Magnus