Remove Emscripten support

CMakeLists.txt

 # See docs/CMake.html for instructions about how to build LLVM with CMake.
 
 cmake_minimum_required(VERSION 2.8.12.2)
 
 if (NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
   message(STATUS "No build type selected, default to Debug")
   set(CMAKE_BUILD_TYPE "Debug")
 endif()
 
 if(POLICY CMP0022)
@@ skipping 164 matching lines @@
 set(LLVM_BINARY_DIR       ${CMAKE_CURRENT_BINARY_DIR}  ) # --prefix
 
 set(LLVM_EXAMPLES_BINARY_DIR ${LLVM_BINARY_DIR}/examples)
 set(LLVM_INCLUDE_DIR ${CMAKE_CURRENT_BINARY_DIR}/include)
 
 set(LLVM_ALL_TARGETS
   AArch64
   ARM
   CppBackend
   Hexagon
-  JSBackend # @LOCALMOD
   Mips
   MSP430
   NVPTX
   PowerPC
   R600
   Sparc
   SystemZ
   X86
   XCore
   )
@@ skipping 499 matching lines @@
     )
 
   if (NOT CMAKE_CONFIGURATION_TYPES)
     add_custom_target(installhdrs
                       DEPENDS ${name}
                       COMMAND "${CMAKE_COMMAND}"
                               -DCMAKE_INSTALL_COMPONENT=llvm-headers
                               -P "${CMAKE_BINARY_DIR}/cmake_install.cmake")
   endif()
 endif()