Separate the PNaCl llc into a tool named pnacl-llc (how original!)

tools/LLVMBuild.txt

Index: tools/LLVMBuild.txt
diff --git a/tools/LLVMBuild.txt b/tools/LLVMBuild.txt
index c301ea9371da12a8c8f889c11a949e14a8f3eabd..d7160f774d5ebb2b636cb51cba41bcba81d32ddd 100644
--- a/tools/LLVMBuild.txt
+++ b/tools/LLVMBuild.txt
@@ -16,7 +16,7 @@
 ;===------------------------------------------------------------------------===;
 
 [common]
-subdirectories = bugpoint llc lli llvm-ar llvm-as llvm-bcanalyzer llvm-cov llvm-diff llvm-dis llvm-dwarfdump llvm-extract llvm-jitlistener llvm-link llvm-mc llvm-nm llvm-objdump llvm-prof llvm-ranlib llvm-rtdyld llvm-size macho-dump opt llvm-mcmarkup pnacl-abicheck pnacl-bcanalyzer pnacl-freeze pnacl-thaw
+subdirectories = bugpoint llc pnacl-llc lli llvm-ar llvm-as llvm-bcanalyzer llvm-cov llvm-diff llvm-dis llvm-dwarfdump llvm-extract llvm-jitlistener llvm-link llvm-mc llvm-nm llvm-objdump llvm-prof llvm-ranlib llvm-rtdyld llvm-size macho-dump opt llvm-mcmarkup pnacl-abicheck pnacl-bcanalyzer pnacl-freeze pnacl-thaw
 
 [component_0]
 type = Group