enable the MSP430 LLVM backend

to let people experiment with this target out of tree.

The MSP430 architecture is used in 16-bit microcontrollers commonly used
in Digital Signal Processing applications.

src/librustc_llvm/build.rs

@@ -66,7 +66,7 @@ fn main() {
     let is_crossed = target != host;
 
     let optional_components =
-        ["x86", "arm", "aarch64", "mips", "powerpc", "pnacl", "systemz", "jsbackend"];
+        ["x86", "arm", "aarch64", "mips", "powerpc", "pnacl", "systemz", "jsbackend", "msp430"];
 
     // FIXME: surely we don't need all these components, right? Stuff like mcjit
     //        or interpreter the compiler itself never uses.

src/librustc_llvm/lib.rs

@@ -413,6 +413,11 @@ pub fn initialize_available_targets() {
                  LLVMInitializeJSBackendTargetInfo,
                  LLVMInitializeJSBackendTarget,
                  LLVMInitializeJSBackendTargetMC);
+    init_target!(llvm_component = "msp430",
+                 LLVMInitializeMSP430TargetInfo,
+                 LLVMInitializeMSP430Target,
+                 LLVMInitializeMSP430TargetMC,
+                 LLVMInitializeMSP430AsmPrinter);
 }
 
 pub fn last_error() -> Option<String> {