Work around GCC 10.0-2's lack of lambda attribute support, closes #605

And bring a few tests outputs up to date

Author: hsutter

include/cpp2util.h

@@ -676,6 +676,11 @@ class out {
         #else
             #define CPP2_LAMBDA_NO_DISCARD
         #endif
+        #if ((__GNUC__ * 100) + __GNUC_MINOR__) < 1003
+            //  GCC 10.2 doesn't support this feature (10.3 is fine)
+            #undef  CPP2_FORCE_INLINE_LAMBDA
+            #define CPP2_FORCE_INLINE_LAMBDA
+        #endif
     #else
         #define CPP2_LAMBDA_NO_DISCARD
     #endif

regression-tests/test-results/clang-12/pure2-bugfix-for-max-munch.cpp.execution

@@ -0,0 +1 @@
+pure2-bugfix-for-max-munch.cpp

regression-tests/test-results/clang-12/pure2-bugfix-for-max-munch.cpp.output

@@ -1,5 +1,5 @@
 
-cppfront compiler v0.2.1   Build 8815:1647
+cppfront compiler v0.2.1   Build 8828:1624
 Copyright(c) Herb Sutter   All rights reserved
 
 SPDX-License-Identifier: CC-BY-NC-ND-4.0

regression-tests/test-results/gcc-13/pure2-bugfix-for-max-munch.cpp.execution

@@ -1 +1 @@
-"8815:1647"
+"8828:1624"