Merge raspbian gcc packaging changes from gcc-9 '9.2.1-21+rpi1' into gcc-10.

diff --cc debian/changelog
index 4e4f82250d3cfa82f468c6efe6815e0dcc16a550,78b631ea9630a01c8eae023c0df91c3a7ad17811..d648ef294a077e006d3d658d718adb419a4d13ae
--- 1/debian/changelog
--- 2/debian/changelog
+++ b/debian/changelog
@@@ -1,97 -1,15 +1,110 @@@
 -gcc-9 (9.2.1-21+rpi1) bullseye-staging; urgency=medium
++gcc-10 (10-20200211-1+rpi1) bullseye-staging; urgency=medium
+ 
+   [changes brought forward from gcc-8 8-20180207-2+rpi1 by Peter Michael Green <plugwash@raspbian.org> at Sat, 17 Feb 2018 00:20:23 +0000]
+   * Don't pass -march=armv7+fp to compiler when building libatomic.
+ 
+   [changes introduced in gcc-8 8.2.0-16+rpi1 by Peter Michael Green]
+   * Disable testsuite (build seems to hang after testsuite completes).
+ 
+   [changes introduced in gcc-9 9.1.0-10+rpi1 by Peter Michael Green]
+   * Update symbols file for raspbian.
+ 
 - -- Raspbian forward porter <root@raspbian.org>  Sun, 08 Dec 2019 03:50:38 +0000
++ -- Peter Michael Green <plugwash@raspbian.org>  Tue, 25 Feb 2020 17:41:07 +0000
++
 +gcc-10 (10-20200211-1) unstable; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20200211, a6ee556c765).
 +
 +  [ Matthias Klose ]
 +  * Let the libgcc-sN multilib cross packages provide libgccN.
 +  * libgcc-sN: Move library back to /lib from /usr/lib, and add
 +    a replaces to libgccN. Closes: #950624.
 +  * libgcc-sN: Add break on cryptsetup-initramfs. Closes: #950551.
 +
 +  [ Aurelien Jarno ]
 +  * debian/libgcc-s.symbols: add mipsn32el to the list of architectures
 +    with GCC_3.3.4, GCC_4.4.0 and CC_4.5.0 symbols.
 +  * debian/rules.conf: libgcc-s1 and corresponding multilib packages are
 +    epochless. Adjust DEB_LIBGCC_VERSION accordingly.
 +
 + -- Matthias Klose <doko@debian.org>  Tue, 11 Feb 2020 07:20:23 +0100
 +
 +gcc-10 (10-20200204-1) unstable; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20200204, 0303907ea5d).
 +  * On architectures where libgcc_s.so is a symlink, replace the symlink with
 +    a simple linker script.
 +  * Add breaks on libgcc-N-dev packages on arm64, s390x and sparc64.
 +    Closes: #950550, #950579.
 +
 + -- Matthias Klose <doko@debian.org>  Tue, 04 Feb 2020 15:52:16 +0100
 +
 +gcc-10 (10-20200202-1) unstable; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20200202, 0303907ea5d).
 +
 + -- Matthias Klose <doko@debian.org>  Sun, 02 Feb 2020 11:43:57 +0100
 +
 +gcc-10 (10-20200129-1) experimental; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20200129, 87c3fcfa6bb).
 +  * Update gm2 from the gm2 trunk.
 +  * Fix libgomp-plugin-amdgcn1 package description.
 +  * Bump libgo soversion.
 +  * Reset libgphobos version to 1.
 +  * Apply proposed patch for PR bootstrap/93409.
 +  * Fix building the amdgcn offload compiler with llvm 9.
 +  * Bump standards version.
 +
 + -- Matthias Klose <doko@debian.org>  Wed, 29 Jan 2020 12:34:27 +0100
 +
 +gcc-10 (10-20200117-2) experimental; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20200117, 507de5ee23e).
 +  * Update gm2 from the gm2 trunk.
 +
 +  [ Matthias Klose ]
 +  * Update libgomp symbols files.
 +  * Build-depend on libzstd-dev.
 +  * Revert the fix for PR c/85678, not making -fno-common the default for
 +    current releases and backports.
 +  * Update libstdc++ symbols file.
 +  * Install more AArch64 intrinsic headers.
 +  * Prepare for git updates from a release branch.
 +  * Allow retrying of a native build in case of unreproducible ICEs.
 +
 +  [YunQiang Su]
 +  * Fix buffer overflow in the gcc-search-prefixed-as-ld patch when
 +    strlen(DEFAULT_REAL_TARGET_MACHINE) < multiarch_len. Addresses: #915194.
 +
 + -- Matthias Klose <doko@debian.org>  Fri, 17 Jan 2020 15:56:29 +0100
 +
 +gcc-10 (10-20200104-1) experimental; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20200104, r279880).
 +  * Update newlib to newlib-3.2.0.
 +  * Update gm2 from the gm2 trunk.
 +
 + -- Matthias Klose <doko@debian.org>  Sat, 04 Jan 2020 11:26:06 +0100
 +
 +gcc-10 (10-20191217-1) experimental; urgency=medium
 +
 +  * GCC snapshot, taken from the trunk (20191217, r279456).
 +  * Update newlib to a snapshot from trunk.
 +  * Update gm2 from the gm2 trunk.
 +  * Update symbols files.
 +  * Build without gnat for a first build.
 +  * Build an amdgcn offload compiler.
 +  * Update debian/copyright for gm2, compiler is now GPL-3+, the runtime
 +    libraries GPL-3+ plus GCC Runtime Library Exception, version 3.1.
 +  * Fix libgo build on arm-linux-gnueabi*.
 +  * Update debian/copyright for contrib/unicode.
 +  * libgomp-plugin-nvptx1: Update cuda suggestions. Addresses: #946487.
 +  * Fix buffer overflow in the gcc-search-prefixed-as-ld patch.
 +    Addresses: #946792.
 +  * Don't strip frontends for debugging purposes.
 +
 + -- Matthias Klose <doko@debian.org>  Tue, 17 Dec 2019 12:31:04 +0100
  
  gcc-9 (9.2.1-21) unstable; urgency=medium
  

diff --cc debian/libstdc++6.symbols.common
Simple merge

diff --cc debian/rules.defs
Simple merge

diff --cc debian/rules.patch
index aa1bc106bd46fe7498d84e144d97784940cbc9ee,376d576548fd7c758d3956cb1971ea0d6361e184..0a361142ba91aa9c5faa20018ec1c10f0196b9b0
--- 1/debian/rules.patch
--- 2/debian/rules.patch
+++ b/debian/rules.patch
@@@ -93,8 -90,12 +93,12 @@@ endi
  #     libstdc++-nothumb-check \
  
  hardening_patches =
+ 
+ debian_patches += \
+       raspbian-disable-libatomic-march \
+ 
  ifneq (,$(filter $(derivative),Ubuntu))
 -  ifneq (,$(findstring gcc-9, $(PKGSOURCE)))
 +  ifneq (,$(findstring gcc-10, $(PKGSOURCE)))
      hardening_patches += \
        gcc-distro-specs-doc \
        gcc-default-fortify-source \