component/golang: build with latest slapos gcc

Golang needs a recent enough version of ld (>2.2) and of gcc ( > 5.5 )

This also introduces multiple gcc versions in gcc component, to have finer control over which component uses which version of gcc.

/reviewed-on !436

component/gcc/buildout.cfg

 # GNU C Compiler
-# Mostly required to support languages different than C or C++
+# Required to use a "known good version" of the compiler or to support languages different than C or C++
 [buildout]
 extends =
   ../gettext/buildout.cfg
@@ -50,3 +50,23 @@ configure-options =
 environment =
   LDFLAGS=-Wl,-rpath=${gmp:location}/lib -Wl,-rpath=${mpc:location}/lib -Wl,-rpath=${mpfr:location}/lib
   PATH=${perl:location}/bin:${tar:location}/bin:%(PATH)s
+
+
+[gcc-8.2]
+recipe = slapos.recipe.cmmi
+shared = true
+url = https://ftp.gnu.org/gnu/gcc/gcc-8.2.0/gcc-8.2.0.tar.gz
+md5sum = ee04f0c22a941f5f17d93809387f2729
+configure-options =
+  --disable-bootstrap
+  --disable-multilib
+  --with-gmp=${gmp:location}
+  --with-mpfr=${mpfr:location}
+  --with-mpc=${mpc:location}
+  --enable-languages="c,c++,fortran"
+  --with-isl=${isl:location}
+  --with-ld=${binutils:location}/bin/ld
+  --with-as=${binutils:location}/bin/as
+environment =
+  LDFLAGS=-Wl,-rpath=${gmp:location}/lib -Wl,-rpath=${isl:location}/lib -Wl,-rpath=${mpc:location}/lib -Wl,-rpath=${mpfr:location}/lib
+  PATH=${binutils:location}/bin:${gettext:location}/bin:${perl:location}/bin:${tar:location}/bin:%(PATH)s

component/golang/buildout.cfg

@@ -2,6 +2,7 @@
 [buildout]
 extends =
   ../findutils/buildout.cfg
+  ../gcc/buildout.cfg
   ../git/buildout.cfg
   ../pkgconfig/buildout.cfg
 
@@ -18,6 +19,7 @@ make-targets= cd src && ./all.bash && cp -alf .. ${:location}
 # some testdata files have an issue with slapos.extension.strip.
 post-install = ${findutils:location}/bin/find ${:location}/src -type d -name testdata -exec rm -rf {} \; || true
 environment =
+  PATH=${gcc-8.2:location}/bin:%(PATH)s
   GOROOT_FINAL=${:location}
   ${:environment-extra}
 

component/kumo/buildout.cfg

@@ -29,3 +29,4 @@ environment =
   LD_LIBRARY_PATH=${gcc:location}/lib:${gcc:location}/lib64
   LDFLAGS=-Wl,-rpath=${gcc:location}/lib -Wl,-rpath=${gcc:location}/lib64 -L${zlib:location}/lib -L${openssl:location}/lib -Wl,-rpath=${tokyocabinet:location}/lib -Wl,-rpath=${messagepack:location}/lib -Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${openssl:location}/lib
   PATH=${gcc:location}/bin:${patch:location}/bin:%(PATH)s
+# KumoFS is known not to build with gcc>6, so we use our own gcc which is 5.5
\ No newline at end of file