Merge crate collections into alloc

Author: murarth

src/Cargo.lock

@@ -376,8 +376,8 @@ pub fn debugger_scripts(build: &Build,
         install(&build.src.join("src/etc/rust-windbg.cmd"), &sysroot.join("bin"),
             0o755);
 
+        cp_debugger_script("natvis/liballoc.natvis");
         cp_debugger_script("natvis/libcore.natvis");
-        cp_debugger_script("natvis/libcollections.natvis");
     } else {
         cp_debugger_script("debugger_pretty_printers_common.py");
 
@@ -550,7 +550,6 @@ pub fn rust_src(build: &Build) {
         "src/liballoc_jemalloc",
         "src/liballoc_system",
         "src/libbacktrace",
-        "src/libcollections",
         "src/libcompiler_builtins",
         "src/libcore",
         "src/liblibc",