Fixing FTBS - icc options are confusing the new gcc

0005-icc-options.patch

@@ -0,0 +1,52 @@
+From 4e90d19ea3de6b8938d097d84f6df3fcf6eb0422 Mon Sep 17 00:00:00 2001
+From: Mark Stapp <mjs@voltanet.io>
+Date: Mon, 15 Feb 2021 13:59:02 -0500
+Subject: [PATCH] build: detect ICC, only try ICC options if ICC
+
+Some ICC command-line options can cause confusion for other
+compilers; test for ICC specifically, and only try to use those
+options if ICC is being used.
+
+Signed-off-by: Mark Stapp <mjs@voltanet.io>
+---
+ configure.ac | 13 +++++++++++--
+ 1 file changed, 11 insertions(+), 2 deletions(-)
+
+diff --git a/configure.ac b/configure.ac
+index 266f37a1129..f3d1f38986a 100755
+--- a/configure.ac
++++ b/configure.ac
+@@ -191,6 +191,11 @@ CXXFLAGS="$orig_cxxflags"
+ AC_PROG_CC_C99
+ dnl NB: see C11 below
+ 
++dnl Some special handling for ICC later on
++if test "$CC" = "icc"; then
++    cc_is_icc="yes"
++fi
++
+ PKG_PROG_PKG_CONFIG
+ 
+ dnl it's 2019, sed is sed.
+@@ -252,7 +257,9 @@ AC_DEFUN([AC_LINK_IFELSE_FLAGS], [{
+ 
+ dnl ICC won't bail on unknown options without -diag-error 10006
+ dnl need to do this first so we get useful results for the other options
+-AC_C_FLAG([-diag-error 10006])
++if test "$cc_is_icc" = "yes"; then
++    AC_C_FLAG([-diag-error 10006])
++fi
+ 
+ dnl AC_PROG_CC_C99 may change CC to include -std=gnu99 or something
+ ac_cc="$CC"
+@@ -335,7 +342,9 @@ AC_SUBST([CXX_COMPAT_CFLAGS])
+ dnl ICC emits a broken warning for const char *x = a ? "b" : "c";
+ dnl for some reason the string consts get 'promoted' to char *,
+ dnl triggering a const to non-const conversion warning.
+-AC_C_FLAG([-diag-disable 3179])
++if test "$cc_is_icc" = "yes"; then
++    AC_C_FLAG([-diag-disable 3179])
++fi
+ 
+ if test "$enable_werror" = "yes" ; then
+   WERROR="-Werror"