The LLVM Coding Standards [1] discourages the use of 'else' or 'else if'
after something that interrupts control flow. Bulk fix all instances as
I'm working on this part of LLDB.

[1] https://llvm.org/docs/CodingStandards.html#don-t-use-else-after-a-return

Cppcheck recommends using a const reference for range variables in a
for-each loop.
This avoids unnecessary copying of elements, improving performance.

Caught by cppcheck -
lldb/source/API/SBBreakpoint.cpp:717:22: performance: Range variable
'name' should be declared as const reference. [iterateByValue]
lldb/source/API/SBTarget.cpp:1150:15: performance: Range variable 'name'
should be declared as const reference. [iterateByValue]
lldb/source/Breakpoint/Breakpoint.cpp:888:26: performance: Range
variable 'name' should be declared as const reference. [iterateByValue]
lldb/source/Breakpoint/BreakpointIDList.cpp:262:26: performance: Range
variable 'name' should be declared as const reference. [iterateByValue]

Fix #91213
Fix #91217
Fix #91219
Fix #91220

We check if the next character after `N.` is `*` before we check its
length. Using `split` on the string is cleaner and less error prone than
using indices with `find` and `substr`.

Note: this does not make `N.` mean anything, it just prevents assertion
failures. `N.` is treated the same as an unrecognized breakpoint name:

```
(lldb) breakpoint enable 1
1 breakpoints enabled.
(lldb) breakpoint enable 1.*
1 breakpoints enabled.
(lldb) breakpoint enable 1.
0 breakpoints enabled.
(lldb) breakpoint enable xyz
0 breakpoints enabled.
```

Found via LLDB fuzzers.

`FindBreakpointID` take a BreakpointID and a pointer to a size_t (so you
can get position information). It returns a bool to indicate whether the
id was found in the list or not.

There are 2 callers of this currently and neither one actually uses the
position information, so I removed it. After that, I renamed it to
Contains to more accurately reflect the intent. Additionally, I changed
the argument type from a reference to a value (because BreakpointID is
just a wrapper around 2 integers, copies are cheap).

This overload is completely unused.

BreakpointIDList does not need to know about CommandReturnObject.
BreakpointIDList::FindAndReplaceIDRanges is the last place that uses it
in BreakpointIDList.

Instead of passing in a CommandReturnObject, it now returns an
llvm::Error. The callsite uses the Error to populate the
CommandReturnObject as needed.

There are 2 motivations here:
1.) There is no need to hand out constant references to BreakpointIDs,
they are only 8 bytes big. In addition, every use of this method already
  makes a copy anyway.
2.) Each BreakpointIDList held onto an invalid BreakpointID specifically
to
  prevent lifetime issues. Returning a value means you can return an
  invalid BreakpointID instead of needing to allocate storage for an
  invalid BreakpointID.

This abstraction is leaky and BreakpointIDList does not need to know
about CommandReturnObject.
Additionally, setting the CommandReturnObject inout param to a success
state does very little. The function returns immediately if the input
ArrayRef is empty, and reading
CommandObjectMultiwordBreakpoint::VerifyIDs more closely, the input is
always empty if the previous call to
BreakpointIDList::FindAndReplaceIDRanges failed. If the call was
successful, then the CommandReturnObject is already in a success state.

I have opted to remove the function altogether and inline the
functionality where it was used.

This patch replaces x.hasValue() with x where x is contextually
convertible to bool.