perf symbol: Remove Rust symbol workarounds

Due to an off-by-one error introduced in commit 73bbb94466
("kallsyms: support "big" kernel symbols"), long symbols (which are
currently only produced by Rust) can have their symbol type being
wrongly parsed by kernel/kallsyms.c.

This has been fixed in commit f3f9f42232 ("kallsyms: Fix wrong
"big" kernel symbol type read from procfs"), and these symbols are now
reported correctly.

Drop the workaround in perf symbol that filter out these symbol types.

Specifically, '1' and 'l' can never be generated by nm -- 'u' does
indicate GNU unique, however such symbols are only generated by G++ for
C++ templates, and are never generated by LLVM (LLVM generates weak
symbols in such cases instead).

'N' can appear if symbols exist inside debug sections, and 'n' may
appear for symbols inside note sections, however these sections do not
typically have symbol (and they're explicitly filtered out by kallsyms).

Therefore, the previous occurrence of these symbols types must be due to
the off-by-one error and can be safely removed.

Signed-off-by: Gary Guo <gary@garyguo.net>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Benno Lossin <lossin@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/symbol.c

@@ -104,21 +104,10 @@ static enum dso_binary_type binary_type_symtab[] = {
 
 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
 
-static bool symbol_type__filter(char __symbol_type)
+static bool symbol_type__filter(char symbol_type)
 {
-	// Since 'U' == undefined and 'u' == unique global symbol, we can't use toupper there
-	// 'N' is for debugging symbols, 'n' is a non-data, non-code, non-debug read-only section.
-	// According to 'man nm'.
-	// 'N' first seen in:
-	// ffffffff9b35d130 N __pfx__RNCINvNtNtNtCsbDUBuN8AbD4_4core4iter8adapters3map12map_try_foldjNtCs6vVzKs5jPr6_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
-	// a seemingly Rust mangled name
-	// Ditto for '1':
-	// root@x1:~# grep ' 1 ' /proc/kallsyms
-	// ffffffffb098bc00 1 __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
-	// ffffffffb098bc10 1 _RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
-	char symbol_type = toupper(__symbol_type);
-	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B' ||
-	       __symbol_type == 'u' || __symbol_type == 'l' || __symbol_type == 'N' || __symbol_type == '1';
+	symbol_type = toupper(symbol_type);
+	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
 }
 
 static int prefix_underscores_count(const char *str)