[libcxxabi] Teach CMake better ways to find the libc++ source directory (and misc cleanup).

Summary:
The main section of this patch teaches CMake  a new option `LIBCXXABI_LIBCXX_PATH` that specifies the path to the libcxx source root. This information is passed to lit so that it can better find libc++'s python module. `LIBCXXABI_LIBCXX_PATH` is also used to help find the libc++ headers.

The rest of this patch is misc cleanup, mostly to make pep8 and pylint happy.
I've also copied libc++'s .gitignore into libc++abi.



Reviewers: jroelofs, danalbert

Reviewed By: danalbert

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D7130

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@226855 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b26d5f7
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,54 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+#lib/ # We actually have things checked in to lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.cache
+nosetests.xml
+coverage.xml
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/