Fix build failures for ppc64el and armhf

debian/changelog

@@ -1,3 +1,10 @@
+rustc (1.55.0+dfsg1-2) UNRELEASED; urgency=medium
+
+  * Actually work around segfault on ppc64el.
+  * Fix FTBFS on armhf caused by GCC 11 changes.
+
+ -- Ximin Luo <infinity0@debian.org>  Wed, 13 Oct 2021 23:46:57 +0100
+
 rustc (1.55.0+dfsg1-1) unstable; urgency=medium
 
   * Upload to unstable.

debian/patches/series

@@ -7,6 +7,7 @@ u-85807.patch
 0001-Revert-Auto-merge-of-79547.patch
 u-reproducible-build.patch
 u-ignore-endian-big-diff.patch
+u-cc-627.patch
 
 # not forwarded, or forwarded but unlikely to be merged
 u-ignore-ppc-hangs.patch

debian/patches/u-cc-627.patch

@@ -0,0 +1,16 @@
+Forwarded: https://github.com/alexcrichton/cc-rs/pull/627
+
+--- a/vendor/cc/src/lib.rs
++++ b/vendor/cc/src/lib.rs
+@@ -1559,6 +1559,11 @@
+                     && target.contains("-linux-")
+                 {
+                     cmd.args.push("-march=armv7-a".into());
++
++                    if target.ends_with("eabihf") {
++                        // lowest common denominator FPU
++                        cmd.args.push("-mfpu=vfpv3-d16".into());
++                    }
+                 }
+ 
+                 // (x86 Android doesn't say "eabi")

debian/rules

@@ -53,7 +53,7 @@ RUSTBUILD_TEST_FLAGS =
 # https://github.com/rust-lang/rust/issues/89744
 # TODO: remove when we update cargo to 1.55 / 0.56
 # upstream bug still exists and is under investigation, but is hidden by newer cargo
-export CARGO_PROFILE_RELEASE_BUILD_OVERRIDE_OPT_LEVEL=3
+export CARGO_PROFILE_RELEASE_BUILD_OVERRIDE_OPT_LEVEL=0
 
 update-version:
 	oldver=$(shell $(SED_RUSTC_BUILDDEP) | sed -ne 's/.*(<= \(.*\)).*/\1/gp' | $(SED_VERSION_SHORT)); \