[Perf] (MG_Util): replace the builtin-shadowing string scans with one tokenize and a SPIR-V OpName pass

RenameBuiltinShadowingFunction probed the whole source ten times per compile
(5 names x mask + scan, each a full-text pass) and still had two blind spots:
a 5-name list and single-line-definition-only detection. On Complementary-scale
packs (4.5MB of sources) that was ~68% of the compile phase.

The rename is now split by FAILURE LAYER, both halves sharing one name table
header so they cannot drift:

- A SPIR-V OpName pass in SanitizeAndOptimizeBinary covers the full ESSL 3.20
  builtin set (~146 names). Renaming a function id is safe by construction:
  builtin calls are GLSL.std.450 instructions and can never resolve to a user
  OpFunction, overloads are distinct ids (a helper overload delegating to the
  real builtin keeps working), dead preprocessor branches never reach SPIR-V,
  and macro-expanded definitions are covered. ESSL 3.x is the only consumer
  that forbids the redefinitions, and this pass runs before its transpile.

- A lexical pass covers only the 5 names whose exact-signature redefinitions
  glslang's relaxed parse rejects outright (never producing SPIR-V for the
  backstop): the historical fma/max3/min3/round/tanh. One TokenizeCode pass;
  definition detection requires brace depth 0, a type-identifier previous
  token that is neither a statement keyword nor a directive tail, and skips
  files whose token-level braces do not balance (preprocessor-asymmetric
  arms) - over-detection is unrecoverable, so every ambiguity falls through
  to the backstop.

Measured on the compile phase (prefix-diff, 3-run medians, Espryt/NVIDIA):
complementary-reimagined 20.0s -> 5.5s, BSL 2.14s -> 1.85s. bliss (the pack
that ships from-scratch fma/tanh helpers) stays at SSIM 0.999962.

Tests: end-to-end ESSL assertions for the multiline-definition and
new-overload shapes, the three adversarial-review reproductions (statement-
keyword call under asymmetric braces, dead-#if compat shim, overload
delegating to the shadowed builtin), and a source-level assertion pinning
the lexical half specifically.

CMakeLists.txt

@@ -194,6 +194,7 @@ set(SOURCE_FILES
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/FlattenInterfaceStructPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/EliminateFloatEqualsZeroPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/RenameSamplerFunctionParameterPass.cpp
+    MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/RenameBuiltinShadowingFunctionsPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/DecomposeWorkgroupVec3Pass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/DecoratePositionInvariantPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/LowerDrawParametersPass.cpp