Move SourceMap to syntax_pos

This does not update the use sites or delete the now unnecessary
SourceMapper trait, to allow git to interpret the file move as a rename
rather than a new file.

Cargo.lock

@@ -4445,6 +4445,7 @@ version = "0.0.0"
 dependencies = [
  "arena",
  "cfg-if",
+ "log",
  "rustc_data_structures",
  "rustc_index",
  "rustc_macros",

src/libsyntax/lib.rs

@@ -92,7 +92,7 @@ pub mod json;
 pub mod ast;
 pub mod attr;
 pub mod expand;
-pub mod source_map;
+pub use syntax_pos::source_map;
 pub mod entry;
 pub mod feature_gate;
 pub mod mut_visit;

src/libsyntax_pos/Cargo.toml

@@ -18,3 +18,4 @@ arena = { path = "../libarena" }
 scoped-tls = "1.0"
 unicode-width = "0.1.4"
 cfg-if = "0.1.2"
+log = "0.4"

src/libsyntax_pos/lib.rs

@@ -16,6 +16,8 @@
 
 use rustc_serialize::{Encodable, Decodable, Encoder, Decoder};
 
+pub mod source_map;
+
 pub mod edition;
 use edition::Edition;
 pub mod hygiene;

src/libsyntax/source_map.rs → src/libsyntax_pos/source_map.rs

@@ -7,8 +7,8 @@
 //! within the `SourceMap`, which upon request can be converted to line and column
 //! information, source code snippets, etc.
 
-pub use syntax_pos::*;
-pub use syntax_pos::hygiene::{ExpnKind, ExpnData};
+pub use crate::*;
+pub use crate::hygiene::{ExpnKind, ExpnData};
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::StableHasher;
@@ -216,7 +216,7 @@ impl SourceMap {
         self.try_new_source_file(filename, src)
             .unwrap_or_else(|OffsetOverflowError| {
                 eprintln!("fatal error: rustc does not support files larger than 4GB");
-                errors::FatalError.raise()
+                crate::fatal_error::FatalError.raise()
             })
     }