[llvm-opt-report] Don't support sources with #pragma

[vfdff]

• mass.c:

__attribute__((noinline))
void demo (double * a, int N){
#pragma clang loop vectorize(assume_safety)
 for (int i = 0; i < N; i++)
   a[i] = 2.0 * a[i];
}

• the test is very similar to PR9944, but add extra #pragma clang loop vectorize(assume_safety), then the llvm-opt-report will report error

error: YAML:2:1: error: Type, Pass, Name or Function missing

• issue reproduce method

  step1: clang -Dmass_EXPORTS -march=armv9-a -O3 -c mass.c -S -w -fsave-optimization-record -g3
  step2: llvm-opt-report mass.opt.yaml -o mass.opt.lst