re PR d/90863 (ICE in StatementSemanticVisitor::visit, at d/dmd/statementsem.c:1992)

	PR d/90863
d/dmd: Merge upstream dmd 6e44734cc

Fixes segmentation fault in StatementSemanticVisitor::visit.

Reviewed-on: https://github.com/dlang/dmd/pull/10033

From-SVN: r272352

gcc/d/dmd/MERGE

-7afcc60c30554e452eacdfbefc4951ebf601fccd
+6e44734ccbeb78252a52e129a67fefb313679948
 
 The first line of this file holds the git revision number of the last
 merge done from the dlang/dmd repository.

gcc/d/dmd/blockexit.c

@@ -496,6 +496,8 @@ int blockExit(Statement *s, FuncDeclaration *func, bool mustNotThrow)
         }
     };
 
+    if (!s)
+        return BEfallthru;
     BlockExit be(func, mustNotThrow);
     s->accept(&be);
     return be.result;

gcc/d/dmd/statementsem.c

@@ -2035,7 +2035,7 @@ public:
         ss->_body = semantic(ss->_body, sc);
         sc->noctor--;
 
-        if (conditionError || ss->_body->isErrorStatement())
+        if (conditionError || (ss->_body && ss->_body->isErrorStatement()))
             goto Lerror;
 
         // Resolve any goto case's with exp
@@ -2111,7 +2111,7 @@ public:
         {
             ss->hasNoDefault = 1;
 
-            if (!ss->isFinal && !ss->_body->isErrorStatement())
+            if (!ss->isFinal && (!ss->_body || !ss->_body->isErrorStatement()))
                 ss->error("switch statement without a default; use 'final switch' or add 'default: assert(0);' or add 'default: break;'");
 
             // Generate runtime error if the default is hit

gcc/testsuite/gdc.test/fail_compilation/fail19955.d

+// PERMUTE_ARGS:
+/*
+TEST_OUTPUT:
+---
+fail_compilation/fail19955.d(8): Error: `switch` statement without a `default`; use `final switch` or add `default: assert(0);` or add `default: break;`
+---
+*/
+void f() { switch(1) static assert(1); }