Remove unnecessary libcxx/compiler-rt components from Green Dragon build process

[penryu]

Summary

The use of libcxx and compiler-rt in the LLDB build is unnecessary and a drain on time and builder resources. LLDB only requires llvm and clang source to build, and the compiler-rt-enabled compiler is already built elsewhere in the jenkins system.

This is part of a larger effort to decrease the build time of the LLDB project.

1. extract latest ASAN/TSAN-enabled host-compiler into workspace (build.py fetch)
2. ensure test inferiors build with proper instrumentation
3. remove compiler-rt and libcxx from list of required projects in build.py
4. remove libcxx/compiler-rt checkouts from workspace
5. verify python tests pass using host-compiler

[tfiala]

Looks good, Tim!

[penryu]

Sending zorg/jenkins/build.py
Transmitting file data .done
Committing transaction...
Committed revision 286311.

[penryu]

r286311

zorg/jenkins/build.py

 
 def derive_lldb():
     """Build a derived src tree for LLDB"""
-    derive(tree='lldb', repos=['lldb', 'llvm', 'clang', 'libcxx',
-                               'compiler-rt'])
+    derive(tree='lldb', repos=['lldb', 'llvm', 'clang'])
 
 
 def create_builddirs():