[test] Use abspath instead of realpath sometimes

[rupprecht]

Summary

In these two cases, use of os.path.realpath is problematic:

• The name of the compiler is significant [1] . For testing purposes, we might provide a compiler called "clang" which is actually a symlink to some build script (which does some flag processing before invoking the real clang). The destination the symlink may not be called "clang", but we still want it to be treated as such.
• When using a build system that puts build artifacts in an arbitrary build location, and later creates a symlink for it (e.g. creates a "<lldb root>/lldbsuite/test/dotest.py" symlinks that points to "/build/artifact/<hash>/dotest.py"), looking at the realpath will not match the "test" convention required here.

[1] See Makefile.rules in the lldb tree, e.g. we use different flags if the compiler is named "clang"

lldb/packages/Python/lldbsuite/test/dotest.py

def parseOptionsAndInitTestdirs():
 
     if args.set_inferior_env_vars:
         lldbtest_config.inferior_env = ' '.join(args.set_inferior_env_vars)
 
     if args.h:
         do_help = True
 
     if args.compiler:
-        configuration.compiler = os.path.realpath(args.compiler)
+        configuration.compiler = os.path.abspath(args.compiler)
         if not is_exe(configuration.compiler):
             configuration.compiler = which(args.compiler)
         if not is_exe(configuration.compiler):
             logging.error(
                     '%s is not a valid compiler executable; aborting...',
                     args.compiler)
             sys.exit(-1)
     else:
def setupSysPath():
     Add LLDB.framework/Resources/Python to the search paths for modules.
     As a side effect, we also discover the 'lldb' executable and export it here.
     """
 
     # Get the directory containing the current script.
     if "DOTEST_PROFILE" in os.environ and "DOTEST_SCRIPT_DIR" in os.environ:
         scriptPath = os.environ["DOTEST_SCRIPT_DIR"]
     else:
-        scriptPath = os.path.dirname(os.path.realpath(__file__))
+        scriptPath = os.path.dirname(os.path.abspath(__file__))
     if not scriptPath.endswith('test'):
         print("This script expects to reside in lldb's test directory.")
         sys.exit(-1)
 
     os.environ["LLDB_TEST"] = scriptPath
     os.environ["LLDB_TEST_SRC"] = lldbsuite.lldb_test_root
 
     # Set up the root build directory.