populate_base_sdk: Stop running gcc --version all the time

Running 'gcc --version' for every image recipe is slow and increases parsing
time/resource usage for no good reason. Only compute the value in when we're
really running the task/function.

(From OE-Core rev: bf49316bb9913b7c89de64d6a194be31aa66e16b)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/utils.py

@@ -342,9 +342,12 @@ def format_pkg_list(pkg_dict, ret_format=None):
 
     return '\n'.join(output)
 
-def host_gcc_version(d):
+def host_gcc_version(d, taskcontextonly=False):
     import re, subprocess
 
+    if taskcontextonly and d.getVar('BB_WORKERCONTEXT') != '1':
+        return
+
     compiler = d.getVar("BUILD_CC")
     try:
         env = os.environ.copy()