Rename `FileSpec::IsRelativeToCurrentWorkingDirectory` to `IsRelative`.

Summary:
`IsRelativeToCurrentWorkingDirectory` was misleading, because relative paths
are sometimes appended to other directories, not just the cwd. Plus, the new
name is shorter. Also added `IsAbsolute` for completeness.

Reviewers: clayborg, ovyalov

Reviewed By: ovyalov

Subscribers: tberghammer, lldb-commits

Differential Revision: http://reviews.llvm.org/D10262

llvm-svn: 239419
diff --git a/lldb/source/Target/TargetList.cpp b/lldb/source/Target/TargetList.cpp
index 70ccd04..552e951 100644
--- a/lldb/source/Target/TargetList.cpp
+++ b/lldb/source/Target/TargetList.cpp
@@ -412,7 +412,7 @@
         if (file.GetFileType() == FileSpec::eFileTypeDirectory)
             user_exe_path_is_bundle = true;
 
-        if (file.IsRelativeToCurrentWorkingDirectory() && user_exe_path)
+        if (file.IsRelative() && user_exe_path)
         {
             // Ignore paths that start with "./" and "../"
             if (!((user_exe_path[0] == '.' && user_exe_path[1] == '/') ||