Bug 1515808 - Compensate for older python's buggy inspect.getblock. r=nalexander

Fixing this unveils an issue in TestRecursiveMake::test_linkage that
was happening locally but not on automation, due to the Binary()
template never being invoked on automation.

Differential Revision: https://phabricator.services.mozilla.com/D15162

--HG--
extra : moz-landing-system : lando

python/mozbuild/mozbuild/frontend/reader.py

@@ -394,6 +394,11 @@ class TemplateFunction(object):
         code = func.func_code
         firstlineno = code.co_firstlineno
         lines = sandbox._current_source.splitlines(True)
+        if lines:
+            # Older versions of python 2.7 had a buggy inspect.getblock() that
+            # would ignore the last line if it didn't terminate with a newline.
+            if not lines[-1].endswith('\n'):
+                lines[-1] += '\n'
         lines = inspect.getblock(lines[firstlineno - 1:])
 
         # The code lines we get out of inspect.getsourcelines look like

python/mozbuild/mozbuild/test/backend/common.py

@@ -209,6 +209,7 @@ CONFIGS = defaultdict(lambda: {
         'defines': {},
         'non_global_defines': [],
         'substs': {
+            'CC_TYPE': 'clang',
             'COMPILE_ENVIRONMENT': '1',
             'LIB_SUFFIX': 'a',
             'BIN_SUFFIX': '.exe',