[docs/debugging-the-compiler] Move asserting on first diagnostic out of the type checker section into its own section.

These options do not make sense just in the type checker section since they can
also be used to diagnose why SIL passes emit diagnostics as well.

Since the prose was originally written, I also added an additional option to
assert on the first warning emitting. I added that to the documentation.

Author: gottesmm

docs/DebuggingTheCompiler.rst

@@ -67,6 +67,25 @@ print the SIL *and* the LLVM IR, you have to run the compiler twice.
 The output of all these dump options (except ``-dump-ast``) can be redirected
 with an additional ``-o <file>`` option.
 
+Debugging Diagnostic Emission
+-----------------------------
+
+Asserting on first emitted Warning/Assert Diagnostic
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When changing the type checker and various SIL passes, one can cause a series of
+cascading diagnostics (errors/warnings) to be emitted. Since Swift does not by
+default assert when emitting such diagnostics, it becomes difficult to know
+where to stop in the debugger. Rather than trying to guess/check if one has an
+asserts swift compiler, one can use the following options to cause the
+diagnostic engine to assert on the first error/warning:
+
+* -Xllvm -swift-diagnostics-assert-on-error=1
+* -Xllvm -swift-diagnostics-assert-on-warning=1
+
+These allow one to dump a stack trace of where the diagnostic is being emitted
+(if run without a debugger) or drop into the debugger if a debugger is attached.
+
 Debugging the Type Checker
 --------------------------
 
@@ -131,16 +150,6 @@ typing ``:constraints debug on``::
   ***  Type ':help' for assistance.              ***
   (swift) :constraints debug on
 
-Asserting on First Error
-~~~~~~~~~~~~~~~~~~~~~~~~
-
-When changing the typechecker, one can cause a series of cascading errors. Since
-Swift doesn't assert on such errors, one has to know more about the typechecker
-to know where to stop in the debugger. Rather than doing that, one can use the
-option ``-Xllvm -swift-diagnostics-assert-on-error=1`` to cause the
-DiagnosticsEngine to assert upon the first error, providing the signal that the
-debugger needs to know that it should attach.
-
 Debugging on SIL Level
 ----------------------