moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

cranelift/umbrella/src/lib.rs

@@ -0,0 +1,50 @@
+//! Cranelift umbrella crate, providing a convenient one-line dependency.
+
+#![deny(
+    missing_docs,
+    trivial_numeric_casts,
+    unused_extern_crates,
+    unstable_features
+)]
+#![warn(unused_import_braces)]
+#![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::new_without_default))]
+#![cfg_attr(
+    feature = "cargo-clippy",
+    warn(
+        clippy::float_arithmetic,
+        clippy::mut_mut,
+        clippy::nonminimal_bool,
+        clippy::option_map_unwrap_or,
+        clippy::option_map_unwrap_or_else,
+        clippy::print_stdout,
+        clippy::unicode_not_nfc,
+        clippy::use_self
+    )
+)]
+#![no_std]
+
+/// Provide these crates, renamed to reduce stutter.
+pub use cranelift_codegen as codegen;
+pub use cranelift_frontend as frontend;
+
+/// A prelude providing convenient access to commonly-used cranelift features. Use
+/// as `use cranelift::prelude::*`.
+pub mod prelude {
+    pub use crate::codegen;
+    pub use crate::codegen::entity::EntityRef;
+    pub use crate::codegen::ir::condcodes::{FloatCC, IntCC};
+    pub use crate::codegen::ir::immediates::{Ieee32, Ieee64, Imm64, Uimm64};
+    pub use crate::codegen::ir::types;
+    pub use crate::codegen::ir::{
+        AbiParam, Ebb, ExtFuncData, ExternalName, GlobalValueData, InstBuilder, JumpTableData,
+        MemFlags, Signature, StackSlotData, StackSlotKind, TrapCode, Type, Value,
+    };
+    pub use crate::codegen::isa;
+    pub use crate::codegen::settings::{self, Configurable};
+
+    pub use crate::frontend::{FunctionBuilder, FunctionBuilderContext, Variable};
+}
+
+/// Version number of this crate.
+pub const VERSION: &str = env!("CARGO_PKG_VERSION");