[PATCH 7/7] gdb/testsuite: Handle "symtab" option on windows-msvc

On windows-msvc, lld-link does not emit a COFF symbol table by
default, even with -debug or -debug:pdb (but does with -debug:dwarf),
so most no-debug-info testcases fail, as they can't run to main, etc.

Handle a "symtab" option request by passing -Wl,-debug:symtab to
lld-link.

Change-Id: Idfd81e80c24dc27f4878a572b8efbea4c4fe9269
---
 gdb/testsuite/lib/gdb.exp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 084f6ff8358..772f69d9633 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -6838,6 +6838,18 @@ proc gdb_compile {source dest type options} {
 	    } else {
 		error "No idea how to force DWARF-5 in this compiler"
 	    }
+	} elseif { $opt == "symtab" } {
+	    if { [istarget "*-*-windows-msvc*"] } {
+		# lld-link does not emit a COFF symbol table by
+		# default, even with -debug or -debug:pdb.  Note
+		# -debug:dwarf implies -debug:symtab, and order does
+		# not matter.  Order matters only when settings
+		# conflict -- e.g., /debug:symtab /debug:nosymtab
+		# leaves symtab off (nosymtab wins, last-applied).
+		lappend new_options "ldflags=-Wl,-debug:symtab"
+	    } else {
+		# All other systems emit a symbol table by default.
+	    }
 	} else {
 	    lappend new_options $opt
 	}
-- 
2.54.0