make it work on aarch64

refered here for similar issue: skade/leveldb#32

Author: phanikishoreg

src/object.rs

@@ -42,7 +42,7 @@ impl<'a> Iterator for Symbols<'a> {
     type Item = Symbol<'a>;
     fn next(&mut self) -> Option<Symbol<'a>> {
         unsafe {
-            let name = util::to_str(object::LLVMGetSymbolName(self.iter) as *mut i8);
+            let name = util::to_str(object::LLVMGetSymbolName(self.iter) as *mut libc::c_char);
             let size = object::LLVMGetSymbolSize(self.iter) as usize;
             let address = object::LLVMGetSymbolAddress(self.iter) as usize;
             Some(Symbol {

src/value.rs

@@ -64,7 +64,7 @@ impl Value {
     pub fn get_name(&self) -> Option<&str> {
         unsafe {
             let c_name = core::LLVMGetValueName(self.into());
-            util::to_null_str(c_name as *mut i8)
+            util::to_null_str(c_name as *mut libc::c_char)
         }
     }
     /// Sets the name of this value
@@ -398,4 +398,4 @@ impl GetContext for Value {
     fn get_context(&self) -> &Context {
         self.get_type().get_context()
     }
-}
+}