Relands #149701 which was reverted in
https://github.com/llvm/llvm-project/commit/185ae5cdc695248b58ae017508cc764c19bee5b7
because it broke demangling of Itanium symbols on i386.

The last commit in this PR adds the fix for this (discussed in #160930).
On x86 environments, the prefix of `__cdecl` functions will now be
removed to match DWARF. I opened #161676 to discuss this for the other
calling conventions.

This reverts commit e98f34eb08b2bf7aed787e7f8a7cea9111f044c8.

This broke demangling of Itanium symbols on i386.

Before, functions created using the NativePDB plugin would not know
about their mangled name. This showed when printing a stacktrace. There,
only the function name was shown. For
https://github.com/llvm/llvm-project/issues/143149, the mangled function
name is required to separate different parts.

This PR adds that name if available.

The Clang AST nodes also take in a mangled name, which was previously
unset. I don't think this unblocks anything further, because Clang can
mangle the function anyway.

After parsing blocks in a function, the blocks should be marked as
parsed for them to be dumped (see
[Function::Dump](https://github.com/llvm/llvm-project/blob/e6aefbec782dbb57f72eb0ae399ed944fe49db2e/lldb/source/Symbol/Function.cpp#L446-L447)).
As explained in
https://github.com/llvm/llvm-project/issues/114906#issuecomment-3255016266,
this happens (accidentally?) in the DIA plugin when parsing variables,
because it calls `function.GetBlock(can_create=true)` which marks blocks
as parsed. In the native plugin, this was never called, so blocks and
variables were never included in the `lldb-test symbols` output.

The `variables.test` for the DIA plugin tests this. One difference
between the plugins is how they specify the location of local variables.
This causes the output of the native plugin to be two lines per
variable, whereas the DIA plugin has one line:
```
(native):
000002C4B7593020:       Variable{0x1c800001}, name = "var_arg1", type = {0000000000000744} 0x000002C4B6CA7900 (int), scope = parameter, location = 0x00000000:
        [0x000000014000102c, 0x000000014000103e): DW_OP_breg7 RSP+8
```
```
(DIA):
000002778C827EE0:       Variable{0x0000001b}, name = "var_arg1", type = {0000000000000005} 0x000002778C1FBAB0 (int), scope = parameter, decl = VariablesTest.cpp:32, location = DW_OP_breg7 RSP+8
```
In the test, I filtered lines starting with spaces followed by `[0x`, so
we can still use `CHECK-NEXT`.

---

Another difference between the plugins is that DIA marks the `this`
pointer as artificial (equivalent to DWARF). This is done if a
variable's object kind is `ObjectPtr`
([source](https://github.com/llvm/llvm-project/blob/ab898f32c60689d1d47d0b6de66c30d3476994bb/lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp#L1050)).
As far as I know, there isn't anything in the debug info that says "this
variable is the `this` pointer" other than the name/type of a variable
and the type of the function.

%T has been deprecated for about seven years, mostly because it is not
unique to each test which can lead to races. This patch updates the few
remaining tests in lldb that use %T to not use it (either directly using
files or creating their own temp dir). The eventual goal is to remove
support for %T from llvm-lit given few tests use it and it still has
racey behavior.

This patch errors on the side of creating new temp dirs even when not
strictly necessary to avoid needing to update filenames inside filecheck
matchers.

The pdb lldb tests do not work correctly with both the VS2019 and VS2017 toolsets at the moment. This change updates several of the tests to work with both toolsets. Unfortunately, this makes the tests suboptimal for both toolsets, but we can update them to be better for VS2019 once we officially drop VS2017. This change is meant to bridge the gap until the update happens, so that the buildbots can work with either toolset.

Differential Revision: https://reviews.llvm.org/D115482

This reverts commit 525a591f0f48b9d54018bf5245f2abee09c9c1c8.

Fixed an issue with pointers to members based on typedefs. In this case,
LLVM would emit a second UDT. I fixed it by not passing the class type
to getTypeIndex when the base type is not a function type. lowerType
only uses the class type for direct function types. This suggests if we
have a PMF with a function typedef, there may be an issue, but that can
be solved separately.

> Before this patch, S_[L|G][THREAD32|DATA32] records were emitted with a simple name, not the fully qualified name (namespace + class scope).
>
> Differential Revision: https://reviews.llvm.org/D79447

This causes asserts in Chromium builds:

CodeViewDebug.cpp:2997: void llvm::CodeViewDebug::emitDebugInfoForUDTs(const std::vector<std::pair<std::string, const DIType *>> &):
Assertion `OriginalSize == UDTs.size()' failed.

I will follow up on the Phabricator issue.

Before this patch, S_[L|G][THREAD32|DATA32] records were emitted with a simple name, not the fully qualified name (namespace + class scope).

Differential Revision: https://reviews.llvm.org/D79447

The original patch got reverted because it broke `check-lldb` on a clean
build. This fixes that.

llvm-svn: 374201