Add wrapper for sccache command in Linux and macOS

The sccache tends to fail every now and then. Adding a wrapper
which calls build tools directly if first call with sccacche fails.

Task-number: COIN-740
Pick-to: 6.2 6.3 6.4
Change-Id: Ic03cf991da585d1569387118183763497ea73b72
Reviewed-by: Toni Saario <toni.saario@qt.io>

coin/provisioning/common/unix/sccache.sh

@@ -62,4 +62,11 @@ function installSccache {
 
     # disable sccache server from shutting down after being idle
     SetEnvVar "SCCACHE_IDLE_TIMEOUT" "0"
+
+    # copy sccache wrapper and place as a first in PATH
+    mkdir -p $HOME/sccache_wrapper
+    cp ${BASH_SOURCE%/*}/sccache_wrapper $HOME/sccache_wrapper/sccache
+    chmod 755 $HOME/sccache_wrapper/sccache
+    SetEnvVar "PATH" "$HOME/sccache_wrapper:\$PATH"
+
 }

coin/provisioning/common/unix/sccache_wrapper

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Call real sccache with original arguments
+# sccache /opt/android/android-ndk-r23b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang --target=aarch64-none ......
+real_sccache=/usr/local/sccache/sccache
+$real_sccache "$@"
+retval=$?
+
+if test $retval -ne 0
+then
+    echo "Sccache command failed, re-try calling build tool directly"
+    "$@"
+    retval=$?
+fi
+exit $retval