Use an amd64 Debian Buster sysroot for building

One of the transitive opencv dependencies needs the newer libc.

Change-Id: I4964bc753aa0dc51c9481896354e272c13a164d5
diff --git a/tools/cpp/CROSSTOOL b/tools/cpp/CROSSTOOL
index c15eddf..5ebddd4 100644
--- a/tools/cpp/CROSSTOOL
+++ b/tools/cpp/CROSSTOOL
@@ -150,20 +150,22 @@
   supports_gold_linker: false
   supports_thin_archives: false
   needsPic: true
-  compiler_flag: "--sysroot=external/clang_6p0_repo/"
+  compiler_flag: "--sysroot=external/amd64_debian_sysroot"
   compiler_flag: "-nostdinc"
   compiler_flag: "-isystem"
-  compiler_flag: "external/clang_6p0_repo/usr/include/x86_64-linux-gnu"
+  compiler_flag: "external/amd64_debian_sysroot/usr/include/c++/7"
+  compiler_flag: "-isystem"
+  compiler_flag: "external/amd64_debian_sysroot/usr/include/x86_64-linux-gnu/c++/7"
+  compiler_flag: "-isystem"
+  compiler_flag: "external/amd64_debian_sysroot/usr/include/c++/8/backward"
+  compiler_flag: "-isystem"
+  compiler_flag: "external/amd64_debian_sysroot/usr/lib/gcc/x86_64-linux-gnu/8/include"
   compiler_flag: "-isystem"
   compiler_flag: "external/clang_6p0_repo/usr/lib/llvm-6.0/lib/clang/6.0.0/include"
   compiler_flag: "-isystem"
-  compiler_flag: "external/clang_6p0_repo/usr/include/c++/7.4.0"
+  compiler_flag: "external/amd64_debian_sysroot/usr/include/x86_64-linux-gnu"
   compiler_flag: "-isystem"
-  compiler_flag: "external/clang_6p0_repo/usr/include/x86_64-linux-gnu/c++/7.4.0"
-  compiler_flag: "-isystem"
-  compiler_flag: "external/clang_6p0_repo/usr/include/c++/7.4.0/backward"
-  compiler_flag: "-isystem"
-  compiler_flag: "external/clang_6p0_repo/usr/include"
+  compiler_flag: "external/amd64_debian_sysroot/usr/include"
   compiler_flag: "-D__STDC_FORMAT_MACROS"
   compiler_flag: "-D__STDC_CONSTANT_MACROS"
   compiler_flag: "-D__STDC_LIMIT_MACROS"
@@ -190,19 +192,19 @@
   compiler_flag: "-fno-omit-frame-pointer"
   compiler_flag: "-pipe"
   compiler_flag: "-ggdb3"
-  cxx_flag: "-isystem"
-  cxx_flag: "external/clang_6p0_repo/usr/include"
   linker_flag: "-nodefaultlibs"
-  linker_flag: "--sysroot=external/clang_6p0_repo/"
+  linker_flag: "--sysroot=external/amd64_debian_sysroot"
   linker_flag: "-lstdc++"
   linker_flag: "-lc"
   linker_flag: "-lgcc"
   linker_flag: "-lgcc_s"
   linker_flag: "-Bexternal/clang_6p0_repo/usr/bin/"
   linker_flag: "-Ltools/cpp/clang_6p0/clang_more_libs"
-  linker_flag: "-Lexternal/clang_6p0_repo/lib/x86_64-linux-gnu"
-  linker_flag: "-Lexternal/clang_6p0_repo/usr/lib/x86_64-linux-gnu"
-  linker_flag: "-Lexternal/clang_6p0_repo/usr/lib/gcc/x86_64-linux-gnu"
+  linker_flag: "-Lexternal/amd64_debian_sysroot/usr/lib/gcc/x86_64-linux-gnu/7/"
+  linker_flag: "-Lexternal/amd64_debian_sysroot/usr/lib/x86_64-linux-gnu/"
+  linker_flag: "-Lexternal/amd64_debian_sysroot/usr/lib/"
+  linker_flag: "-Lexternal/amd64_debian_sysroot/lib/x86_64-linux-gnu/"
+  linker_flag: "-Lexternal/amd64_debian_sysroot/lib/"
   linker_flag: "-no-canonical-prefixes"
   linker_flag: "-fuse-ld=gold"
   linker_flag: "-Wl,-z,relro,-z,now"
@@ -224,12 +226,10 @@
   linking_mode_flags {
     mode: DYNAMIC
   }
-  cxx_builtin_include_directory: "%package(@clang_6p0_repo//usr)%/include/c++/7.4.0"
-  cxx_builtin_include_directory: "%package(@clang_6p0_repo//usr)%/include/x86_64-linux-gnu/c++/7.4.0"
-  cxx_builtin_include_directory: "%package(@clang_6p0_repo//usr)%/include/c++/7.4.0/backward"
-  cxx_builtin_include_directory: "%package(@clang_6p0_repo//usr)%/local/include"
   cxx_builtin_include_directory: "%package(@clang_6p0_repo//usr)%/lib/llvm-6.0/lib/clang/6.0.0/include"
-  cxx_builtin_include_directory: "%package(@clang_6p0_repo//usr)%/include/x86_64-linux-gnu"
+  cxx_builtin_include_directory: "%package(@amd64_debian_sysroot//usr)%/include"
+  cxx_builtin_include_directory: "%package(@amd64_debian_sysroot//usr)%/lib/gcc/x86_64-linux-gnu/7/include"
+  cxx_builtin_include_directory: "%package(@amd64_debian_sysroot//usr)%/lib/gcc/x86_64-linux-gnu/7/include-fixed"
   builtin_sysroot: ""
   unfiltered_cxx_flag: "-no-canonical-prefixes"
   unfiltered_cxx_flag: "-Wno-builtin-macro-redefined"