Update to latest wasi-libc (formerly wasi-sysroot) and llvm 8.0.1.

The wasi-libc update here brings numerous bug fixes and minor changes,
and __wasilibc_rmfileat has been renamed to __wasilibc_unlinkat.

The only WebAssembly-relevant patch in the LLVM 8.0.1 update here is
4b1712f7, a fix for using /dev/null as the output file.

.gitmodules

@@ -2,9 +2,9 @@
 	path = src/llvm-project
 	url = https://github.com/llvm/llvm-project
 	branch = release/8.x
-[submodule "src/wasi-sysroot"]
-	path = src/wasi-sysroot
-	url = https://github.com/CraneStation/wasi-sysroot
+[submodule "src/wasi-libc"]
+	path = src/wasi-libc
+	url = https://github.com/CraneStation/wasi-libc
 [submodule "src/config"]
 	path = src/config
 	url = https://git.savannah.gnu.org/git/config.git

Makefile

@@ -40,11 +40,11 @@ build/llvm.BUILT:
 		llvm-config
 	touch build/llvm.BUILT
 
-build/wasi-sysroot.BUILT: build/llvm.BUILT
-	make -C $(ROOT_DIR)/src/wasi-sysroot \
+build/wasi-libc.BUILT: build/llvm.BUILT
+	make -C $(ROOT_DIR)/src/wasi-libc \
 		WASM_CC=$(PREFIX)/bin/clang \
 		SYSROOT=$(PREFIX)/share/sysroot
-	touch build/wasi-sysroot.BUILT
+	touch build/wasi-libc.BUILT
 
 build/compiler-rt.BUILT: build/llvm.BUILT
 	mkdir -p build/compiler-rt
@@ -67,7 +67,7 @@ build/compiler-rt.BUILT: build/llvm.BUILT
 	cp -R $(ROOT_DIR)/build/llvm/lib/clang $(PREFIX)/lib/
 	touch build/compiler-rt.BUILT
 
-build/libcxx.BUILT: build/llvm.BUILT build/compiler-rt.BUILT build/wasi-sysroot.BUILT
+build/libcxx.BUILT: build/llvm.BUILT build/compiler-rt.BUILT build/wasi-libc.BUILT
 	mkdir -p build/libcxx
 	cd build/libcxx; cmake -G "Unix Makefiles" \
 		-DCMAKE_TOOLCHAIN_FILE=$(ROOT_DIR)/wasi-sdk.cmake \
@@ -134,7 +134,7 @@ build/config.BUILT:
 	cp src/config/config.sub src/config/config.guess $(PREFIX)/share/misc
 	touch build/config.BUILT
 
-build: build/llvm.BUILT build/wasi-sysroot.BUILT build/compiler-rt.BUILT build/libcxxabi.BUILT build/libcxx.BUILT build/config.BUILT
+build: build/llvm.BUILT build/wasi-libc.BUILT build/compiler-rt.BUILT build/libcxxabi.BUILT build/libcxx.BUILT build/config.BUILT
 
 strip: build/llvm.BUILT
 	cd $(PREFIX)/bin; strip clang-8 llc lld llvm-ar

README.md

@@ -8,10 +8,10 @@
 
 This repository contains no compiler or library code itself; it uses
 git submodules to pull in the upstream Clang and LLVM tree, as well as the
-wasi-sysroot tree.
+wasi-libc tree.
 
-The Sysroot portion of this SDK is the
-[wasi-sysroot](https://github.com/CraneStation/wasi-sysroot).
+The libc portion of this SDK is the
+[wasi-libc](https://github.com/CraneStation/wasi-libc).
 
 Upstream Clang and LLVM 8.0 can compile for WASI out of the box, and WebAssembly
 support is included in them by default. So, all that's done here is to provide

src/llvm-project

@@ -1 +1 @@
-Subproject commit 05288f5020de74ced1c22a11d9406ee2c90bb807
+Subproject commit e3dc222bd3ce1060e82ab2a8f2802a18abac834c

src/wasi-libc

@@ -0,0 +1 @@
+Subproject commit 92eaf255a1c484e92292157ccf4d22e7d43f033e

src/wasi-sysroot

@@ -1 +0,0 @@
-Subproject commit 8e8cc34aadefb45955e706503fe70f582b3e3606