testsuite: Fix lambda-vis.C for targets with user label prefix '_'.

This prepends an optional match for the additional USER_LABEL_PREFIX
to the scan assembler checks.

2020-03-22  Iain Sandoe  <iain@sandoe.co.uk>

	* g++.dg/abi/lambda-vis.C: Amend assembler match
	strings for targets using a USER_LABEL_PREFIX.

gcc/testsuite/ChangeLog

+2020-03-22  Iain Sandoe  <iain@sandoe.co.uk>
+
+	* g++.dg/abi/lambda-vis.C: Amend assembler match
+	strings for targets using a USER_LABEL_PREFIX.
+
 2020-03-22  Iain Buclaw  <ibuclaw@gdcproject.org>
 
 	PR d/93038

gcc/testsuite/g++.dg/abi/lambda-vis.C

@@ -13,11 +13,11 @@ int gvar = gfoo (capture ([]{}));
 
 inline int ivar = ifoo (capture ([]{}));
 
-// { dg-final { scan-assembler {_Z7captureINL4svarMUlvE_EE7WrapperIT_EOS2_:} } }
-// { dg-final { scan-assembler {_Z7captureIN4gvarMUlvE_EE7WrapperIT_EOS2_:} } }
-// { dg-final { scan-assembler {_Z7captureIN4ivarMUlvE_EE7WrapperIT_EOS2_:} } }
+// { dg-final { scan-assembler {_?_Z7captureINL4svarMUlvE_EE7WrapperIT_EOS2_:} } }
+// { dg-final { scan-assembler {_?_Z7captureIN4gvarMUlvE_EE7WrapperIT_EOS2_:} } }
+// { dg-final { scan-assembler {_?_Z7captureIN4ivarMUlvE_EE7WrapperIT_EOS2_:} } }
 
 // Calls to the foos are emitted.
-// { dg-final { scan-assembler {call[ \t]*_Z4sfooI7WrapperINL4svarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } }
-// { dg-final { scan-assembler {call[ \t]*_Z4gfooI7WrapperIN4gvarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } }
-// { dg-final { scan-assembler {call[ \t]*_Z4ifooI7WrapperIN4ivarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } }
+// { dg-final { scan-assembler {call[ \t]*_?_Z4sfooI7WrapperINL4svarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } }
+// { dg-final { scan-assembler {call[ \t]*_?_Z4gfooI7WrapperIN4gvarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } }
+// { dg-final { scan-assembler {call[ \t]*_?_Z4ifooI7WrapperIN4ivarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } }