R: fix build on ppc

srcpkgs/R/patches/ppc.patch

@@ -0,0 +1,33 @@
+From 1b588f18b1802de3370515181f9ba04a2dee3f42 Mon Sep 17 00:00:00 2001
+From: maechler <maechler@00db46b3-68df-0310-9c12-caf00c1e9a41>
+Date: Wed, 25 Mar 2020 09:06:23 +0000
+Subject: [PATCH] update (1 / LDBL_EPSILON) to all __powerpc__
+
+git-svn-id: https://svn.r-project.org/R/trunk@78054 00db46b3-68df-0310-9c12-caf00c1e9a41
+---
+ src/main/arithmetic.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/src/main/arithmetic.c b/src/main/arithmetic.c
+index fc7496a8908..196431c7675 100644
+--- src/main/arithmetic.c
++++ src/main/arithmetic.c
+@@ -1,6 +1,6 @@
+ /*
+  *  R : A Computer Language for Statistical Data Analysis
+- *  Copyright (C) 1998--2019 The R Core Team.
++ *  Copyright (C) 1998--2020 The R Core Team.
+  *  Copyright (C) 2003--2019 The R Foundation
+  *  Copyright (C) 1995--1997 Robert Gentleman and Ross Ihaka
+  *
+@@ -178,8 +178,9 @@ void attribute_hidden InitArithmetic()
+ 
+ 
+ #if HAVE_LONG_DOUBLE && (SIZEOF_LONG_DOUBLE > SIZEOF_DOUBLE)
+-# ifdef __PPC64__
++# ifdef __powerpc__
+  // PowerPC 64 (when gcc has -mlong-double-128) fails constant folding with LDOUBLE
++ // Debian Bug#946836 shows it is needed also for 32-bit ppc, not just __PPC64__
+ #  define q_1_eps (1 / LDBL_EPSILON)
+ # else
+ static LDOUBLE q_1_eps = 1 / LDBL_EPSILON;