Revert "all: use compiler-rt from the llvm-project directory"

This reverts commit acdaaa1.
See #734 for details.

Author: aykevl

.gitmodules

@@ -10,3 +10,7 @@
 [submodule "lib/cmsis-svd"]
 	path = lib/cmsis-svd
 	url = https://github.com/tinygo-org/cmsis-svd
+[submodule "lib/compiler-rt"]
+	path = lib/compiler-rt
+	url = https://github.com/llvm-mirror/compiler-rt.git
+	branch = release_80

Makefile

@@ -258,16 +258,16 @@ release: tinygo gen-device
 	@mkdir -p build/release/tinygo/pkg/armv7m-none-eabi
 	@mkdir -p build/release/tinygo/pkg/armv7em-none-eabi
 	@echo copying source files
-	@cp -p  build/tinygo$(EXE)                     build/release/tinygo/bin
+	@cp -p  build/tinygo$(EXE)           build/release/tinygo/bin
 	@cp -p $(abspath $(CLANG_SRC))/lib/Headers/*.h build/release/tinygo/lib/clang/include
-	@cp -rp lib/CMSIS/CMSIS/Include                build/release/tinygo/lib/CMSIS/CMSIS
-	@cp -rp lib/CMSIS/README.md                    build/release/tinygo/lib/CMSIS
-	@cp -rp llvm-project/compiler-rt/lib/builtins  build/release/tinygo/lib/compiler-rt/lib
-	@cp -rp llvm-project/compiler-rt/LICENSE.TXT   build/release/tinygo/lib/compiler-rt
-	@cp -rp llvm-project/compiler-rt/README.txt    build/release/tinygo/lib/compiler-rt
-	@cp -rp lib/nrfx/*                             build/release/tinygo/lib/nrfx
-	@cp -rp src                                    build/release/tinygo/src
-	@cp -rp targets                                build/release/tinygo/targets
+	@cp -rp lib/CMSIS/CMSIS/Include      build/release/tinygo/lib/CMSIS/CMSIS
+	@cp -rp lib/CMSIS/README.md          build/release/tinygo/lib/CMSIS
+	@cp -rp lib/compiler-rt/lib/builtins build/release/tinygo/lib/compiler-rt/lib
+	@cp -rp lib/compiler-rt/LICENSE.TXT  build/release/tinygo/lib/compiler-rt
+	@cp -rp lib/compiler-rt/README.txt   build/release/tinygo/lib/compiler-rt
+	@cp -rp lib/nrfx/*                   build/release/tinygo/lib/nrfx
+	@cp -rp src                          build/release/tinygo/src
+	@cp -rp targets                      build/release/tinygo/targets
 	./build/tinygo build-builtins -target=armv6m-none-eabi  -o build/release/tinygo/pkg/armv6m-none-eabi/compiler-rt.a
 	./build/tinygo build-builtins -target=armv7m-none-eabi  -o build/release/tinygo/pkg/armv7m-none-eabi/compiler-rt.a
 	./build/tinygo build-builtins -target=armv7em-none-eabi -o build/release/tinygo/pkg/armv7em-none-eabi/compiler-rt.a

builder/builtins.go

@@ -166,12 +166,6 @@ func builtinFiles(target string) []string {
 
 // builtinsDir returns the directory where the sources for compiler-rt are kept.
 func builtinsDir() string {
-	// Path from within the development directory.
-	path := filepath.Join(goenv.Get("TINYGOROOT"), "llvm-project", "compiler-rt", "lib", "builtins")
-	if _, err := os.Stat(path); err == nil {
-		return path
-	}
-	// Path from within an installation directory (bundled in the release tarball).
 	return filepath.Join(goenv.Get("TINYGOROOT"), "lib", "compiler-rt", "lib", "builtins")
 }