PNaCl dynamic linking: Build an initial dynamically-linked newlib-based libc

src/untrusted/pll_loader/nacl.scons

Index: src/untrusted/pll_loader/nacl.scons
diff --git a/src/untrusted/pll_loader/nacl.scons b/src/untrusted/pll_loader/nacl.scons
index 2bacdd928503e74609f9c0fc3907d4e9815e86c7..257ec065cc6b28d660c9d344be35f192b6281b31 100644
--- a/src/untrusted/pll_loader/nacl.scons
+++ b/src/untrusted/pll_loader/nacl.scons
@@ -8,4 +8,10 @@ Import('env')
 if not env.Bit('bitcode'):
   Return()
 
-env.ComponentLibrary('pll_loader', ['pll_loader.cc'])
+env.ComponentLibrary('pll_loader_lib', ['pll_loader.cc'])
+
+# Ideally we would want to build an executable here (using
+# ComponentProgram()), but Scons makes it difficult for a nacl.scons file
+# in tests/ to refer to an executable built in src/untrusted/, because the
+# two can use different subdirectories of scons-out/.
+env.ComponentLibrary('pll_loader_main', ['pll_loader_main.cc'])