Remove Emscripten support

lib/Target/JSBackend/LLVMBuild.txt

Index: lib/Target/JSBackend/LLVMBuild.txt
diff --git a/lib/Target/JSBackend/LLVMBuild.txt b/lib/Target/JSBackend/LLVMBuild.txt
deleted file mode 100644
index 30e0a2848f41aef508eab28134fac5e033679d0a..0000000000000000000000000000000000000000
--- a/lib/Target/JSBackend/LLVMBuild.txt
+++ /dev/null
@@ -1,31 +0,0 @@
-;===- ./lib/Target/JSBackend/LLVMBuild.txt --------------------*- Conf -*--===;
-;
-;                     The LLVM Compiler Infrastructure
-;
-; This file is distributed under the University of Illinois Open Source
-; License. See LICENSE.TXT for details.
-;
-;===------------------------------------------------------------------------===;
-;
-; This is an LLVMBuild description file for the components in this subdirectory.
-;
-; For more information on the LLVMBuild system, please see:
-;
-;   http://llvm.org/docs/LLVMBuild.html
-;
-;===------------------------------------------------------------------------===;
-
-[common]
-subdirectories = MCTargetDesc TargetInfo
-
-[component_0]
-type = TargetGroup
-name = JSBackend
-parent = Target
-
-[component_1]
-type = Library
-name = JSBackendCodeGen
-parent = JSBackend
-required_libraries = Analysis CodeGen Core JSBackendInfo JSBackendDesc NaClTransforms Support Target
-add_to_library_groups = JSBackend