Use `MapVector` so `GCStrategyMap` can support forward and reverse
iterator, which is required in `AsmPrinter`.

Analyses should be marked as analyses.

Otherwise they are prone to get ignored by the legacy analysis cache mechanism and get scheduled redundantly.

Identified with misc-include-cleaner.

Replace it with a forward declaration instead. Analysis.h is pulled in
by all passes, but not all passes need to access the module.

- `CollectorMetadataAnalysis` provides `GCStrategyMap`.
- `GCFunctionAnalysis` provides `GCFunctionInfo`.

`GCStrategyMap` owns `GCStrategy` pointers and this
pass is used by `AsmPrinter` to iterate all GC strategies.

Most passes that require `GCModuleInfo` actually require the
`GCFunctionInfo`,
so add `GCFunctionAnalysis` for convenience.

This pass is broken and looks like no one uses it for the last 15+ years.

```c++
bool Printer::runOnFunction(Function &F) {
  if (F.hasGC())
    return false;

  GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F);
```
```c++
GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) {
  assert(!F.isDeclaration() && "Can only get GCFunctionInfo for a definition!");
  assert(F.hasGC()); // Equivalent to `assert(false);` when called by `Printer::runOnFunction`
```

See also #74972.

This is a (fixed) recommit of https://reviews.llvm.org/D121169

after:  1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121681

This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169

after:  1061034926
before: 1063332844

Differential Revision: https://reviews.llvm.org/D121169