Fix error reporting for parallel parsed function blocks.

tests_lit/parse_errs/parallel.ll

+; Test that we report a bug at the same place, independent of a parallel parse.
+
+; REQUIRES: no_minimal_build
+
+; RUN: %p2i --expect-fail -i %s --args -threads=0 -parse-parallel=0 \
+; RUN:      -allow-externally-defined-symbols | FileCheck %s
+
+; RUN: %p2i --expect-fail -i %s --args -threads=1 -parse-parallel=1 \
+; RUN:      -allow-externally-defined-symbols | FileCheck %s
+
+declare i32 @f();
+
+declare i64 @g();
+
+define void @Test(i32 %ifcn) {
+entry:
+  %fcn =  inttoptr i32 %ifcn to i1()*
+  %v = call i1 %fcn()
+
+; CHECK: Error(222:6): Return type of function is invalid: i1
+
+  ret void
+}