[LLVM-3.9] Configure PIE at the module level instead of compilation unit level

This was deleted here[1] which appears to be replaced by this[2]
which is a new setPIELevel function on the LLVM module itself.

[1]: http://reviews.llvm.org/D19753
[2]: http://reviews.llvm.org/D19671

Author: badboy

src/librustc_llvm/lib.rs

@@ -2155,6 +2155,7 @@ extern {
 
     pub fn LLVMRustSetComdat(M: ModuleRef, V: ValueRef, Name: *const c_char);
     pub fn LLVMRustUnsetComdat(V: ValueRef);
+    pub fn LLVMRustSetModulePIELevel(M: ModuleRef);
 }
 
 // LLVM requires symbols from this library, but apparently they're not printed

src/librustc_trans/context.rs

@@ -352,6 +352,7 @@ unsafe fn create_context_and_module(sess: &Session, mod_name: &str) -> (ContextR
     let llvm_target = sess.target.target.llvm_target.as_bytes();
     let llvm_target = CString::new(llvm_target).unwrap();
     llvm::LLVMRustSetNormalizedTarget(llmod, llvm_target.as_ptr());
+    llvm::LLVMRustSetModulePIELevel(llmod);
     (llcx, llmod)
 }
 

src/rustllvm/PassWrapper.cpp

@@ -188,7 +188,10 @@ LLVMRustCreateTargetMachine(const char *triple,
     }
 
     TargetOptions Options;
+#if LLVM_VERSION_MINOR <= 8
     Options.PositionIndependentExecutable = PositionIndependentExecutable;
+#endif
+
     Options.FloatABIType = FloatABI::Default;
     if (UseSoftFloat) {
         Options.FloatABIType = FloatABI::Soft;
@@ -411,3 +414,10 @@ extern "C" LLVMTargetDataRef
 LLVMRustGetModuleDataLayout(LLVMModuleRef M) {
     return wrap(&unwrap(M)->getDataLayout());
 }
+
+extern "C" void
+LLVMRustSetModulePIELevel(LLVMModuleRef M) {
+#if LLVM_VERSION_MINOR >= 9
+    unwrap(M)->setPIELevel(PIELevel::Level::Default);
+#endif
+}