⚡️ Do not compile cmock.c if no mocks used

If a particular test executable does not include mocks, there’s no reason to compile and link cmock.c. This small improvement will almost certainly have quite little impact, but it’s just more better, dangit.

lib/ceedling/test_invoker.rb

@@ -305,7 +305,7 @@ def setup_and_invoke(tests:, context:TEST_SYM, options:{})
           end
 
           # CMock + Unity + CException
-          test_frameworks    = @helper.collect_test_framework_sources
+          test_frameworks    = @helper.collect_test_framework_sources( details[:mock_list] )
 
           # Extra suport source files (e.g. microcontroller startup code needed by simulator)
           test_support       = @configurator.collection_all_support

lib/ceedling/test_invoker_helper.rb

@@ -167,18 +167,18 @@ def flags(context:, operation:, filepath:)
     return @flaginator.flag_down( context:context, operation:operation, filepath:filepath )
   end
 
-  def collect_test_framework_sources
+  def collect_test_framework_sources(mocks)
     sources = []
 
     sources << File.join(PROJECT_BUILD_VENDOR_UNITY_PATH, UNITY_C_FILE)
-    sources << File.join(PROJECT_BUILD_VENDOR_CMOCK_PATH, CMOCK_C_FILE) if @configurator.project_use_mocks
+    sources << File.join(PROJECT_BUILD_VENDOR_CMOCK_PATH, CMOCK_C_FILE) if @configurator.project_use_mocks and !mocks.empty?
     sources << File.join(PROJECT_BUILD_VENDOR_CEXCEPTION_PATH, CEXCEPTION_C_FILE) if @configurator.project_use_exceptions
 
     # If we're (a) using mocks (b) a Unity helper is defined and (c) that unity helper includes a source file component,
     # then link in the unity_helper object file too.
     if @configurator.project_use_mocks
       @configurator.cmock_unity_helper_path.each do |helper|
-        if @file_wrapper.exist?( helper.ext(EXTENSION_SOURCE) )
+        if @file_wrapper.exist?( helper.ext( EXTENSION_SOURCE ) )
           sources << helper
         end
       end