[DebugInfo][DwarfDebug] Move emission of globals from beginModule() to endModule() (5/7) (#184219)HEADmain

RFC
https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544

This patch moves the emission of global variables from
`DwarfDebug::beginModule()` to `DwarfDebug::endModule()`.

It has the following effects:
1. The order of debug entities in the resulting DWARF changes.
2. Currently, if a DISubprogram requires emission of both concrete
out-of-line and inlined subprogram DIEs, and such a subprogram contains
a static local variable, the DIE for the variable is emitted into the
concrete out-of-line subprogram DIE. As a result, the variable is not
available in debugger when breaking at the inlined function instance.

It happens because static locals are emitted in
`DwarfDebug::beginModule()`, but abstract DIEs for functions that are
not completely inlined away are created only later during
`DwarfDebug::endFunctionImpl()` calls.

With this patch, DIEs for static local variables of subprograms that
have both inlined and the concrete out-of-line instances are placed into
abstract subprogram DIEs. They become visible in debugger when breaking
at concrete out-of-line and inlined function instances.

   `llvm/test/DebugInfo/Generic/inlined-static-var.ll` illustrates that.
3. It will allow to simplify abstract subprogram DIEs creation by
reverting https://github.com/llvm/llvm-project/pull/159104 later.

This is needed to simplify DWARF emission in a context of proper support
of function-local static variables which comes in the next patch
(https://reviews.llvm.org/D144008), making all function-local entities
handled in `DwarfDebug::endModuleImpl()`.

Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>
Co-authored-by: David Blaikie <dblaikie@gmail.com>
Co-authored-by: Vladislav Dzhidzhoev <vdzhidzhoev@accesssoftek.com>

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