Export of internal Abseil changes

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b770d03c2f1042d399c3f9576e881691cbe962c4 by Abseil Team <absl-team@google.com>:

Avoid applying the workaround for MSVC's static initialization problems when using clang-cl.

PiperOrigin-RevId: 275870089

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2b8fc02ec49aeb5ad56cef20259cdd7f6ee0c917 by Abseil Team <absl-team@google.com>:

Document return values.

PiperOrigin-RevId: 275839042

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baa99064f9a28b188661df7fba989fcd558818af by Abseil Team <absl-team@google.com>:

Support "auto" and other uncommon builtin types in absl::debugging_internal::Demangle.

PiperOrigin-RevId: 275556195

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f9d5c6a3a0d374dbf105d6e2e9e0c8fa949ed187 by Gennadiy Rozental <rogeeff@google.com>:

Internal rework.

PiperOrigin-RevId: 275550005

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2679a77db5b26349e8c8b2059621af55d2fca139 by Mark Barolak <mbar@google.com>:

Remove a comment reference to the no longer extant ::string implementation.

PiperOrigin-RevId: 275531987

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7b427a7613c44a98c6f13da43b2bff2837ca6b19 by Derek Mauro <dmauro@google.com>:

Upgrade to Bazel 1.0.0 and CMake 3.15.4

PiperOrigin-RevId: 275500823

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81f7d20905debf9d1e300bd2e9899f88d27f632a by Derek Mauro <dmauro@google.com>:

Fix -Wimplicit-int-float-conversion warning in latest clang

PiperOrigin-RevId: 275492439
GitOrigin-RevId: b770d03c2f1042d399c3f9576e881691cbe962c4
Change-Id: I9b39dad524489f0d62c912d02e8ac43761c81e55

1 files changed, 16 insertions, 14 deletions

diff --git a/absl/debugging/stacktrace.h b/absl/debugging/stacktrace.h
index 3fc1c03f3e6b..cd8fae76d536 100644
--- a/absl/debugging/stacktrace.h
+++ b/absl/debugging/stacktrace.h
@@ -36,10 +36,10 @@ namespace absl {
 // GetStackFrames()
 //
 // Records program counter values for up to `max_depth` frames, skipping the
-// most recent `skip_count` stack frames, and stores their corresponding values
-// and sizes in `results` and `sizes` buffers. (Note that the frame generated
-// for the `absl::GetStackFrames()` routine itself is also skipped.)
-// routine itself.
+// most recent `skip_count` stack frames, stores their corresponding values
+// and sizes in `results` and `sizes` buffers, and returns the number of frames
+// stored. (Note that the frame generated for the `absl::GetStackFrames()`
+// routine itself is also skipped.)
 //
 // Example:
 //
@@ -54,8 +54,8 @@ namespace absl {
 // The current stack frame would consist of three function calls: `bar()`,
 // `foo()`, and then `main()`; however, since the `GetStackFrames()` call sets
 // `skip_count` to `1`, it will skip the frame for `bar()`, the most recently
-// invoked function call. It will therefore return two program counters and will
-// produce values that map to the following function calls:
+// invoked function call. It will therefore return 2 and fill `result` with
+// program counters within the following functions:
 //
 //      result[0]       foo()
 //      result[1]       main()
@@ -82,9 +82,10 @@ extern int GetStackFrames(void** result, int* sizes, int max_depth,
 //
 // Records program counter values obtained from a signal handler. Records
 // program counter values for up to `max_depth` frames, skipping the most recent
-// `skip_count` stack frames, and stores their corresponding values and sizes in
-// `results` and `sizes` buffers. (Note that the frame generated for the
-// `absl::GetStackFramesWithContext()` routine itself is also skipped.)
+// `skip_count` stack frames, stores their corresponding values and sizes in
+// `results` and `sizes` buffers, and returns the number of frames stored. (Note
+// that the frame generated for the `absl::GetStackFramesWithContext()` routine
+// itself is also skipped.)
 //
 // The `uc` parameter, if non-null, should be a pointer to a `ucontext_t` value
 // passed to a signal handler registered via the `sa_sigaction` field of a
@@ -105,8 +106,9 @@ extern int GetStackFramesWithContext(void** result, int* sizes, int max_depth,
 // GetStackTrace()
 //
 // Records program counter values for up to `max_depth` frames, skipping the
-// most recent `skip_count` stack frames, and stores their corresponding values
-// in `results`. Note that this function is similar to `absl::GetStackFrames()`
+// most recent `skip_count` stack frames, stores their corresponding values
+// in `results`, and returns the number of frames
+// stored. Note that this function is similar to `absl::GetStackFrames()`
 // except that it returns the stack trace only, and not stack frame sizes.
 //
 // Example:
@@ -131,9 +133,9 @@ extern int GetStackTrace(void** result, int max_depth, int skip_count);
 //
 // Records program counter values obtained from a signal handler. Records
 // program counter values for up to `max_depth` frames, skipping the most recent
-// `skip_count` stack frames, and stores their corresponding values in
-// `results`. (Note that the frame generated for the
-// `absl::GetStackFramesWithContext()` routine itself is also skipped.)
+// `skip_count` stack frames, stores their corresponding values in `results`,
+// and returns the number of frames stored. (Note that the frame generated for
+// the `absl::GetStackFramesWithContext()` routine itself is also skipped.)
 //
 // The `uc` parameter, if non-null, should be a pointer to a `ucontext_t` value
 // passed to a signal handler registered via the `sa_sigaction` field of a