Fix -Wunreachable-code-return with newer clang version.

When the emit_continuing lambda always returns true, clang is able to
detect it and finds that some code is unreachable.

This commit changes places that use the lambdas directly to instead use
the stored emit_continuing_ member.

Bud: dawn:824
Change-Id: Idfd804a6ec53ac793e8988dce79991c659fbbc36
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/75060
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/writer/glsl/generator_impl.cc b/src/writer/glsl/generator_impl.cc
index 6c83e58..dc6a05a 100644
--- a/src/writer/glsl/generator_impl.cc
+++ b/src/writer/glsl/generator_impl.cc
@@ -2110,7 +2110,7 @@
     if (!EmitStatements(stmt->body->statements)) {
       return false;
     }
-    if (!emit_continuing()) {
+    if (!emit_continuing_()) {
       return false;
     }
   }
@@ -2190,7 +2190,7 @@
       return false;
     }
 
-    if (!emit_continuing()) {
+    if (!emit_continuing_()) {
       return false;
     }
   } else {
diff --git a/src/writer/hlsl/generator_impl.cc b/src/writer/hlsl/generator_impl.cc
index 9108f9f..09f946c 100644
--- a/src/writer/hlsl/generator_impl.cc
+++ b/src/writer/hlsl/generator_impl.cc
@@ -3203,7 +3203,7 @@
     if (!EmitStatements(stmt->body->statements)) {
       return false;
     }
-    if (!emit_continuing()) {
+    if (!emit_continuing_()) {
       return false;
     }
   }
@@ -3283,7 +3283,7 @@
       return false;
     }
 
-    if (!emit_continuing()) {
+    if (!emit_continuing_()) {
       return false;
     }
   } else {
diff --git a/src/writer/msl/generator_impl.cc b/src/writer/msl/generator_impl.cc
index a4f8b72..fffd371 100644
--- a/src/writer/msl/generator_impl.cc
+++ b/src/writer/msl/generator_impl.cc
@@ -1827,7 +1827,7 @@
     if (!EmitStatements(stmt->body->statements)) {
       return false;
     }
-    if (!emit_continuing()) {
+    if (!emit_continuing_()) {
       return false;
     }
   }
@@ -1908,7 +1908,7 @@
       return false;
     }
 
-    if (!emit_continuing()) {
+    if (!emit_continuing_()) {
       return false;
     }
   } else {