Added reportPendingErrors to SkSL code generation

This fixes an assertion failure uncovered by the fuzzer.

Bug: oss-fuzz:37469
Change-Id: I626c003cfa8a0bc65851899df3a7695dbe29200b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/441311
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>

gn/sksl_tests.gni

@@ -188,6 +188,7 @@ sksl_spirv_tests = [
   "/sksl/spirv/Ossfuzz35916.sksl",
   "/sksl/workarounds/RewriteMatrixVectorMultiply.sksl",
   "/sksl/errors/Ossfuzz36850.sksl",
+  "/sksl/errors/Ossfuzz37469.sksl",
   "/sksl/errors/UndefinedFunction.sksl",
   "/sksl/errors/UnusedInterfaceBlock.sksl",
 ]

resources/sksl/errors/Ossfuzz37469.sksl

@@ -0,0 +1 @@
+k{int z;}m[];void main(){}

src/sksl/codegen/SkSLSPIRVCodeGenerator.cpp

@@ -3789,6 +3789,7 @@ bool SPIRVCodeGenerator::generateCode() {
     this->writeWord(fIdCount, *fOut);
     this->writeWord(0, *fOut); // reserved, always zero
     write_stringstream(buffer, *fOut);
+    fContext.fErrors->reportPendingErrors(PositionInfo());
     return fContext.fErrors->errorCount() == 0;
 }
 

tests/sksl/errors/Ossfuzz37469.asm.frag

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: runtime-sized arrays are not supported in SPIR-V
+1 error