[gcc r14-1797] c++: Fix templated convertion operator demangling

[Nathan Sidwell <nathan@gcc.gnu.org>]

https://gcc.gnu.org/g:5a897036187468d4ded330b90b2abdaff5061ed6

commit r14-1797-g5a897036187468d4ded330b90b2abdaff5061ed6
Author: Nathan Sidwell <nathan@acm.org>
Date:   Mon Jun 12 19:37:04 2023 -0400

    c++: Fix templated convertion operator demangling
    
    Instantiations of templated conversion operators failed to demangle
    for cases such as 'operator X<int>', but worked for 'operator X<int>
    &', due to thinking the template instantiation of X was the
    instantiation of the conversion operator itself.
    
            libiberty/
            * cp-demangle.c (d_print_conversion): Remove incorrect
            template instantiation handling.
            * testsuite/demangle-expected: Add testcases.

Diff:
---
 libiberty/cp-demangle.c               | 28 +++-------------------------
 libiberty/testsuite/demangle-expected | 27 +++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 25 deletions(-)

diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index 18ab28fd028..3bd303a7544 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -6660,32 +6660,10 @@ d_print_conversion (struct d_print_info *dpi, int options,
       dpt.template_decl = dpi->current_template;
     }
 
-  if (d_left (dc)->type != DEMANGLE_COMPONENT_TEMPLATE)
-    {
-      d_print_comp (dpi, options, d_left (dc));
-      if (dpi->current_template != NULL)
-	dpi->templates = dpt.next;
-    }
-  else
-    {
-      d_print_comp (dpi, options, d_left (d_left (dc)));
-
-      /* For a templated cast operator, we need to remove the template
-	 parameters from scope after printing the operator name,
-	 so we need to handle the template printing here.  */
-      if (dpi->current_template != NULL)
-	dpi->templates = dpt.next;
+  d_print_comp (dpi, options, d_left (dc));
 
-      if (d_last_char (dpi) == '<')
-	d_append_char (dpi, ' ');
-      d_append_char (dpi, '<');
-      d_print_comp (dpi, options, d_right (d_left (dc)));
-      /* Avoid generating two consecutive '>' characters, to avoid
-	 the C++ syntactic ambiguity.  */
-      if (d_last_char (dpi) == '>')
-	d_append_char (dpi, ' ');
-      d_append_char (dpi, '>');
-    }
+  if (dpi->current_template != NULL)
+    dpi->templates = dpt.next;
 }
 
 /* Initialize the information structure we use to pass around
diff --git a/libiberty/testsuite/demangle-expected b/libiberty/testsuite/demangle-expected
index 52dff883a18..0acd2d635db 100644
--- a/libiberty/testsuite/demangle-expected
+++ b/libiberty/testsuite/demangle-expected
@@ -1662,3 +1662,30 @@ X<int>::F()::{lambda(int)#1}::operator()(int) const
 
 _Z1fIiEv1AIXnxtlT_EEE
 void f<int>(A<noexcept(int{})>)
+
+_ZNO1Ycv1XEv
+Y::operator X() &&
+
+_ZNO1Ycv1XIT_EIvEEv
+Y::operator X<void><void>() &&
+
+_ZNO1Y3bobEv
+Y::bob() &&
+
+_ZNR1Y3bobEv
+Y::bob() &
+
+_ZNKR1YcvRK1XIT_EIvEEv
+Y::operator X<void> const&<void>() const &
+
+_ZZN1XIiEcviEvE1y
+X<int>::operator int()::y
+
+_ZZN1XIiEcv1ZIiEEvE1y
+X<int>::operator Z<int>()::y
+
+_ZZN1Xcv1ZIT_EIiEEvE1y
+X::operator Z<int><int>()::y
+
+_ZZN1XIfEcv1ZIT_EIiEEvE1y
+X<float>::operator Z<int><int>()::y