fixes a C code generator regression, no need to backport, only the 1.4 line is affected (#15569)

tests/ccgbugs/t2procs.nim

@@ -0,0 +1,18 @@
+discard """
+  output: '''before
+1
+before
+2'''
+"""
+
+proc fn[T1, T2](a: T1, b: T2) =
+  a(1)
+  b(2)
+
+fn( (proc(x: int) =
+      echo "before" # example block, can span multiple lines
+      echo x),
+    (proc (y: int) =
+      echo "before"
+      echo y)
+)