[infra] Assembles the SDK using GN rather than create_sdk.py

build/toolchain/linux/BUILD.gn

Index: build/toolchain/linux/BUILD.gn
diff --git a/build/toolchain/linux/BUILD.gn b/build/toolchain/linux/BUILD.gn
index f92005dfe501b1387c397126151476556589c948..787e54194c755faccfb475a843a77b5edc77f102 100644
--- a/build/toolchain/linux/BUILD.gn
+++ b/build/toolchain/linux/BUILD.gn
@@ -34,6 +34,7 @@ gcc_toolchain("arm") {
   ld = cxx
   readelf = "${prefix}readelf"
   nm = "${prefix}nm"
+  strip = "${prefix}strip"
 
   toolchain_cpu = "arm"
   toolchain_os = "linux"
@@ -53,6 +54,7 @@ gcc_toolchain("arm64") {
   ld = cxx
   readelf = "${prefix}readelf"
   nm = "${prefix}nm"
+  strip = "${prefix}strip"
 
   toolchain_cpu = "arm64"
   toolchain_os = "linux"
@@ -62,12 +64,16 @@ gcc_toolchain("arm64") {
 gcc_toolchain("clang_x86") {
   prefix = rebase_path("//buildtools/toolchain/clang+llvm-x86_64-linux/bin",
                        root_build_dir)
-  cc = "${compiler_prefix}$prefix/clang"
-  cxx = "${compiler_prefix}$prefix/clang++"
+  if (toolchain_prefix != "") {
+    prefix = toolchain_prefix
+  }
+  cc = "${compiler_prefix}${prefix}/clang"
+  cxx = "${compiler_prefix}${prefix}/clang++"
   readelf = "readelf"
-  nm = "nm"
-  ar = "ar"
+  nm = "${prefix}/llvm-nm"
+  ar = "${prefix}/llvm-ar"
   ld = cxx
+  strip = "${prefix}/strip"
 
   toolchain_cpu = "x86"
   toolchain_os = "linux"
@@ -75,13 +81,18 @@ gcc_toolchain("clang_x86") {
 }
 
 gcc_toolchain("x86") {
-  cc = "${compiler_prefix}gcc"
-  cxx = "${compiler_prefix}g++"
+  prefix = ""
+  if (toolchain_prefix != "") {
+    prefix = toolchain_prefix
+  }
+  cc = "${compiler_prefix}${prefix}gcc"
+  cxx = "${compiler_prefix}${prefix}g++"
 
-  readelf = "readelf"
-  nm = "nm"
-  ar = "ar"
+  readelf = "${prefix}readelf"
+  nm = "${prefix}nm"
+  ar = "${prefix}ar"
   ld = cxx
+  strip = "${prefix}strip"
 
   toolchain_cpu = "x86"
   toolchain_os = "linux"
@@ -91,13 +102,17 @@ gcc_toolchain("x86") {
 gcc_toolchain("clang_x64") {
   prefix = rebase_path("//buildtools/toolchain/clang+llvm-x86_64-linux/bin",
                        root_build_dir)
-  cc = "${compiler_prefix}$prefix/clang"
-  cxx = "${compiler_prefix}$prefix/clang++"
+  if (toolchain_prefix != "") {
+    prefix = toolchain_prefix
+  }
+  cc = "${compiler_prefix}${prefix}/clang"
+  cxx = "${compiler_prefix}${prefix}/clang++"
 
   readelf = "readelf"
-  nm = "nm"
-  ar = "ar"
+  nm = "${prefix}/llvm-nm"
+  ar = "${prefix}/llvm-ar"
   ld = cxx
+  strip = "${prefix}/strip"
 
   toolchain_cpu = "x64"
   toolchain_os = "linux"
@@ -105,13 +120,18 @@ gcc_toolchain("clang_x64") {
 }
 
 gcc_toolchain("x64") {
-  cc = "${compiler_prefix}gcc"
-  cxx = "${compiler_prefix}g++"
+  prefix = ""
+  if (toolchain_prefix != "") {
+    prefix = toolchain_prefix
+  }
+  cc = "${compiler_prefix}${prefix}gcc"
+  cxx = "${compiler_prefix}${prefix}g++"
 
-  readelf = "readelf"
-  nm = "nm"
-  ar = "ar"
+  readelf = "${prefix}readelf"
+  nm = "${prefix}nm"
+  ar = "${prefix}ar"
   ld = cxx
+  strip = "${prefix}strip"
 
   toolchain_cpu = "x64"
   toolchain_os = "linux"
@@ -125,6 +145,7 @@ gcc_toolchain("mipsel") {
   ld = cxx
   readelf = "${toolchain_prefix}readelf"
   nm = "${toolchain_prefix}nm"
+  strip = "${toolchain_prefix}strip"
 
   toolchain_cpu = "${target_cpu}"
   toolchain_os = "linux"